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math/9306215
mu-complete Suslin trees on mu^+
We prove that mu = mu^{< mu}, 2^mu = mu^+ and ``there is a non reflecting stationary subset of mu^+ composed of ordinals of cofinality < mu'' imply that there is a mu-complete Souslin tree on mu^+ .
1993-06-15
2008-02-03
[ "math.LO" ]
Menachem Kojman, Saharon Shelah
math/9305202
\v{C}ech-Stone remainders of spaces that look like $[0,\infty)$
We show that many spaces that look like the half~line~$\halfline=[0,\infty)$ have, under~$\CH$, a \v{C}ech-Stone-remainder that is homeomorphic to~$\Hstar$. We also show that $\CH$ is equivalent to the statement that all standard subcontinua of~$\Hstar$ are homeomorphic. The proofs use Model-theoretic tools like reduce...
1993-05-18
2009-09-25
[ "math.LO" ]
Alan Dow and Klaas Pieter Hart
math/9305206
Topological partition relations to the form omega^*-> (Y)^1_2
Theorem: The topological partition relation omega^{*}-> (Y)^{1}_{2} (a) fails for every space Y with |Y| >= 2^c ; (b) holds for Y discrete if and only if |Y| <= c; (c) holds for certain non-discrete P-spaces Y ; (d) fails for Y= omega cup {p} with p in omega^{*} ; (e) fails for Y infinite and countably compac...
1993-05-15
2015-06-26
[ "math.LO", "math.GN" ]
W. Wistar Comfort, Akio Kato, Saharon Shelah
math/9305205
Every coseparable group may be free
We show that if 2^{aleph_0} Cohen reals are added to the universe, then for every reduced non-free torsion-free abelian group A of cardinality less than the continuum, there is a prime p so that Ext_p(A, Z) not= 0. In particular if it is consistent that there is a supercompact cardinal, then it is consistent (even with...
1993-05-15
2016-09-06
[ "math.LO", "math.RA" ]
Alan H. Mekler, Saharon Shelah
math/9305204
The Ehrenfeucht-Fraisse-game of length omega_1
Let (A) and (B) be two first order structures of the same vocabulary. We shall consider the Ehrenfeucht-Fra{i}sse-game of length omega_1 of A and B which we denote by G_{omega_1}(A,B). This game is like the ordinary Ehrenfeucht-Fraisse-game of L_{omega omega} except that there are omega_1 moves. It is clear that G_{ome...
1993-05-15
2009-09-25
[ "math.LO" ]
Alan H. Mekler, Saharon Shelah, Jouko V\"a\"an\"anen
math/9304205
Sums of Darboux and continuous functions
It is shown that that for every Darboux function $F$ there is a non-constant continuous function $f$ such that $F+f$ is still Darboux. It is shown to be consistent --- the model used is iterated Sacks forcing --- that for every Darboux function $F$ there is a nowhere constant continuous function $f$ such that $F+f$ is ...
1993-04-27
2008-02-03
[ "math.LO" ]
Juris Stepr\=ans
math/9304204
Bounding and dominating number of families of functions on N
We pursue the study of families of functions on the natural numbers, with emphasis here on the bounded families. The situation being more complicated than the unbounded case, we attack the problem by classifying the families according to their bounding and dominating numbers, the traditional scheme for gaps. Many open ...
1993-04-26
2008-02-03
[ "math.LO" ]
Claude Laflamme
math/9304207
Viva la difference II. The Ax-Kochen isomorphism theorem
We show in section 1 that the Ax-Kochen isomorphism theorem requires the continuum hypothesis. Most of the applications of this theorem are insensitive to set theoretic considerations. (A probable exception is the work of Moloney.) In section 2 we give an unrelated result on cuts in models of Peano arithmetic which ans...
1993-04-15
2016-09-06
[ "math.LO", "math.RA" ]
Saharon Shelah
math/9304203
The Consistency of $ZFC+CIFS$
This paper is a technical continuation of ``Natural Axiom Schemata Extending ZFC. Truth in the Universe?'' In that paper we argue that $CIFS$ is a natural axiom schema for the universe of sets. In particular it is a natural closure condition on $V$ and a natural generalization of $IFS(L).$ Here we shall prove the consi...
1993-04-15
2008-02-03
[ "math.LO" ]
Garvin Melles
math/9304202
Natural Internal Forcing Schemata Extending ZFC
Let V be the universe of sets and V_{\alpha} the sets of rank \leq\alpha. We develop some axiom schemata for set theory based on the following three assumptions: 1. V \models ZFC 2. V is large with respect to the class of ordinals 3. V is large with respect to each of the V_{\alpha}
1993-04-12
2016-09-06
[ "math.LO" ]
Garvin Melles
math/9304201
The automorphism group of a saturated model has a large dense free subgroup
We prove that for a stable theory $T,$ if $M$ is a saturated model of $T$ of cardinality $\lambda$ where $\lambda > \big|T\big|,$ then $Aut(M)$ has a dense free subgroup on $2^{\lambda}$ generators. This affirms a conjecture of Hodges.
1993-04-12
2008-02-03
[ "math.LO" ]
Garvin Melles and Saharon Shelah
math/9304208
Borel actions of Polish groups
We show that a {\it Borel} action of a Polish group on a standard Borel space is Borel isomorphic to a {\it continuous} action of the group on a Polish space, and we apply this result to three aspects of the theory of Borel actions of Polish groups: universal actions, invariant probability measures, and the Topological...
1993-04-01
2016-09-06
[ "math.LO", "math.FA" ]
Howard Becker, Alexander S. Kechris
math/9303208
How special are Cohen and random forcings i.e. Boolean algebras of the family of subsets of reals modulo meagre or null
The feeling that those two forcing notions-Cohen and Random-(equivalently the corresponding Boolean algebras Borel(R)/(meager sets), Borel(R)/(null sets)) are special, was probably old and widespread. A reasonable interpretation is to show them unique, or ``minimal'' or at least characteristic in a family of ``nice for...
1993-03-15
2016-09-06
[ "math.LO", "math.FA" ]
Saharon Shelah
math/9303207
On closed P-sets with ccc in the space omega^*
It is proved that -- consistently -- there can be no ccc closed P-sets in the remainder space omega^* .
1993-03-15
2016-09-06
[ "math.LO", "math.GN" ]
Ryszard Frankiewicz, Saharon Shelah, Pawel Zbierski
math/9302203
Combinatorics on Ideals and Axiom A
Throughout this abstract let U be a fixed p-point ultrafilter and let I be the dual ideal. Grigorieff forcing is P(U)={p:omega to 2|dom(p) is an element of I} ordered by reverse inclusion. It is well known that Grigorieff forcing is proper. The main result of this paper is the following: THEOREM: Gregorieff forcing d...
1993-02-26
2016-09-06
[ "math.LO" ]
James Sharp
math/9302202
Full Reflection at a Measurable Cardinal
A stationary subset $S$ of a regular uncountable cardinal $\kappa$ {\it reflects fully} at regular cardinals if for every stationary set $T \subseteq \kappa$ of higher order consisting of regular cardinals there exists an $\alpha \in T$ such that $S \cap \alpha$ is a stationary subset of $\alpha$. {\it Full Reflection}...
1993-02-25
2008-02-03
[ "math.LO" ]
Thomas Jech and Ji\v{r}\'i Witzany
math/9302201
Provable Pi-1-2 Singletons
In this note I show that a pi-1-2 singleton R of L-degree strictly between 0 and 0# can be obtained so as to be the unique solution to a pi-1-2 formula which provably has at most one solution, in the theory ZFC+(*) where (*) has the approximate strength of an ineffable cardinal.
1993-02-04
2008-02-03
[ "math.LO" ]
Sy D. Friedman (MIT)
math/9301210
On the existence of atomic models
We give an example of a countable theory T such that for every cardinal lambda >= aleph_2 there is a fully indiscernible set A of power lambda such that the principal types are dense over A, yet there is no atomic model of T over A. In particular, T(A) is a theory of size lambda where the principal types are dense, yet...
1993-01-15
2008-02-03
[ "math.LO" ]
Michael C. Laskowski, Saharon Shelah
math/9301205
On the number of automorphism of uncontable models
Let s(A) denote the number of automorphisms of a model A of power omega_1. We derive a necessary and sufficient condition in terms of trees for the existence of an A with omega_1 < s(A) < 2^{omega_1}. We study the sufficiency of some conditions for s(A)=2^{omega_1}. These conditions are analogous to conditions studied ...
1993-01-15
2016-09-06
[ "math.LO" ]
Saharon Shelah, Heikki Tuuri, Jouko V\"a\"an\"anen
math/9301207
Explicitly nonstandard uniserial modules
A new construction is given of non-standard uniserial modules over certain valuation domains; the construction resembles that of a special Aronszajn tree in set theory. A consequence is the proof of a sufficient condition for the existence of non-standard uniserial modules; this is a theorem of ZFC which complements an...
1993-01-15
2009-09-25
[ "math.LO", "math.RA" ]
Paul C. Eklof, Saharon Shelah
math/9301206
All meager filters may be null
We show that it is consistent with ZFC that all filters which have the Baire property are Lebesgue measurable. We also show that the existence of a Sierpinski set implies that there exists a nonmeasurable filter which has the Baire property.
1993-01-15
2009-09-25
[ "math.LO" ]
Tomek Bartoszy\'nski, Martin Goldstern, Haim Judah, Saharon Shelah
math/9301203
A variety with solvable, but not uniformly solvable, word problem
In the literature two notions of the word problem for a variety occur. A variety has a decidable word problem if every finitely presented algebra in the variety has a decidable word problem. It has a uniformly decidable word problem if there is an algorithm which given a finite presentation produces an algorithm for so...
1993-01-15
2016-09-06
[ "math.LO", "math.RA" ]
Alan H. Mekler, Evelyn Nelson, Saharon Shelah
math/9301209
Borel partitions of infinite subtrees of a perfect tree
A theorem of Galvin asserts that if the unordered pairs of reals are partitioned into finitely many Borel classes then there is a perfect set P such that all pairs from P lie in the same class. The generalization to n-tuples for n >= 3 is false. Let us identify the reals with 2^omega ordered by the lexicographical orde...
1993-01-15
2016-09-06
[ "math.LO" ]
Alain Louveau, Boban Veli\v{c}kovi\'c, Saharon Shelah
math/9301204
Some compact logics --- results in ZFC
We show that if we enrich first order logic by allowing quantification over isomorphisms between definable ordered fields the resulting logic, L(Q_{Of}), is fully compact. In this logic, we can give standard compactness proofs of various results. Next, we attempt to get compactness results for some other logics without...
1993-01-15
2016-09-06
[ "math.LO" ]
Alan H. Mekler, Saharon Shelah
math/9301208
Forcing isomorphism
A forcing extension may create new isomorphisms between two models of a first order theory. Certain model theoretic constraints on the theory and other constraints on the forcing can prevent this pathology. A countable first order theory is classifiable if it is superstable and does not have either the dimensional orde...
1993-01-15
2016-09-06
[ "math.LO" ]
John T. Baldwin, Michael C. Laskowski, Saharon Shelah
math/9310234
Symmetry of tilings of the plane
We discuss two new results on tilings of the plane. In the first, we give sufficient conditions for the tilings associated with an inflation rule to be uniquely ergodic under translations, the conditions holding for the pinwheel inflation rule. In the second result we prove there are matching rules for the pinwheel inf...
1993-10-01
2008-02-03
[ "math.MG", "math.DS" ]
Charles Radin
math/9307229
A counterexample to Borsuk's conjecture
Let $f(d)$ be the smallest number so that every set in $R^d$ of diameter 1 can be partitioned into $f(d)$ sets of diameter smaller than 1. Borsuk's conjecture was that $f(d)\! =\!d\!+\!1$. We prove that $f(d)\! \ge\! (1.2)^{\sqrt d}$ for large~$d$.
1993-07-01
2008-02-03
[ "math.MG", "math.CO" ]
Jeff Kahn, Gil Kalai
math/9302210
Random polytopes and affine surface area
Let K be a convex body in $R^d$. A random polytope is the convex hull $[x_1,...,x_n]$ of finitely many points chosen at random in K. $\Bbb E(K,n)$ is the expectation of the volume of a random polytope of n randomly chosen points. I. B\'ar\'any showed that we have for convex bodies with $C^3$ boundary and everywhere pos...
1993-02-04
2016-09-06
[ "math.MG", "math.FA" ]
Carsten Sch\"utt
math/9307234
Average case complexity of linear multivariate problems
We study the average case complexity of a linear multivariate problem $(\lmp)$ defined on functions of $d$ variables. We consider two classes of information. The first $\lstd$ consists of function values and the second $\lall$ of all continuous linear functionals. Tractability of $\lmp$ means that the average case comp...
1993-07-01
2025-10-20
[ "math.NA", "cs.NA", "math.CA" ]
Henryk Woźniakowski
math/9304214
Wavelet transforms versus Fourier transforms
This note is a very basic introduction to wavelets. It starts with an orthogonal basis of piecewise constant functions, constructed by dilation and translation. The ``wavelet transform'' maps each $f(x)$ to its coefficients with respect to this basis. The mathematics is simple and the transform is fast (faster than the...
1993-04-01
2025-10-20
[ "math.NA", "cs.NA", "math.CA" ]
Gilbert Strang
math/9304216
Integration and approximation of multivariate functions: average case complexity with isotropic Wiener measure
We study the average case complexity of multivariate integration and $L_2$ function approximation for the class $F=C([0,1]^d)$ of continuous functions of $d$ variables. The class $F$ is endowed with the isotropic Wiener measure (Brownian motion in Levy's sense). Furthermore, for both problems, only function values are ...
1993-04-01
2025-10-20
[ "math.NA", "cs.NA", "math.CA" ]
Grzegorz W. Wasilkowski
math/9307231
On the passage from local to global in number theory
The author surveys the problem of piecing together integral or rational solutions to Diophantine equations (global structure) from solutions modulo congruences and real solutions (local structure).
1993-07-01
2008-02-03
[ "math.NT", "math.AG" ]
Barry Mazur
math/9304211
On the distribution of sums of residues
We generalize and solve the $\roman{mod}\,q$ analogue of a problem of Littlewood and Offord, raised by Vaughan and Wooley, concerning the distribution of the $2^n$ sums of the form $\sum_{i=1}^n\varepsilon_ia_i$, where each $\varepsilon_i$ is $0$ or $1$. For all $q$, $n$, $k$ we determine the maximum, over all reduced ...
1993-04-01
2016-09-06
[ "math.NT", "math.CO" ]
Jerrold R. Griggs
math/9310233
Harmonic analysis of fractal measures induced by representations of a certain C$^*$-algebra
We describe a class of measurable subsets $\Omega$ in $\br^d$ such that $L^2(\Omega)$ has an orthogonal basis of frequencies $e_\lambda(x)=e^{i2\pi\lambda\cdot x}(x\in\Omega)$ indexed by $\lambda\in\Lambda\subset\br^d$. We show that such spectral pairs $(\Omega ,\Lambda)$ have a self-similarity which may be used to gen...
1993-10-01
2016-09-06
[ "math.OA", "math.FA" ]
Palle E. T. Jorgensen, Steen Pedersen
math/9301219
Factorizations of invertible operators and $K$-theory of $C^*$-algebras
Let $\Scr A$ be a unital C*-algebra. We describe \it K-skeleton factorizations \rm of all invertible operators on a Hilbert C*-module $\Scr H_{\Scr A}$, in particular on $\Scr H=l^2$, with the Fredholm index as an invariant. We then outline the isomorphisms $K_0(\Scr A) \cong \pi _{2k}([p]_0)\cong \pi _{2k} ({GL}^p_r(\...
1993-01-01
2009-09-25
[ "math.OA", "math.AT" ]
Shuang Zhang
math/9310225
Coupling and Harnack inequalities for Sierpinski carpets
Uniform Harnack inequalities for harmonic functions on the pre- and graphical Sierpinski carpets are proved using a probabilistic coupling argument. Various results follow from this, including the construction of Brownian motion on Sierpinski carpets embedded in $\R^d$, $d\geq 3$, estimates on the fundamental solution ...
1993-10-01
2016-09-06
[ "math.PR" ]
Martin T. Barlow, Richard F. Bass
math/9310236
The birth of the giant component
Limiting distributions are derived for the sparse connected components that are present when a random graph on $n$ vertices has approximately $\half n$ edges. In particular, we show that such a graph consists entirely of trees, unicyclic components, and bicyclic components with probability approaching $\sqrt{2\over 3} ...
1993-10-01
2008-02-03
[ "math.PR", "math.CO" ]
Svante Janson, Donald E. Knuth, Tomasz {\L}uczak, Boris Pittel
math/9310230
A new measure of growth for countable-dimensional algebras
A new dimension function on countable-dimensional algebras (over a field) is described. Its dimension values for finitely generated algebras exactly fill the unit interval $[0,1]$. Since the free algebra on two generators turns out to have dimension 0 (although conceivably some Noetherian algebras might have positive d...
1993-10-01
2008-02-03
[ "math.RA" ]
John Hannah, K. C. O'Meara
math/9304215
An external approach to unitary representations
The main aim of this paper is to present the ideas which lead first to the solution of the unitarizability problem for $\GL(n)$ over nonarchimedean local fields and to the recognition that the same result holds over archimedean local fields, a result which was proved by Vogan using an internal approach. Let us say that...
1993-04-01
2016-09-06
[ "math.RT" ]
Marko Tadic
math/9301214
Homogeneous functions on light cones: the infinitesimal structure of some degenerate principal series representations
In this paper we study the reducibility, composition series and unitarity of the components of some degenerate principal series representations of $\RMO(p,q)$, $\RMU(p,q)$ and $\SP(p,q)$. This is done by realizing these representations in paces of homogeneous functions on light cones and writing down the explicit actio...
1993-01-01
2009-09-25
[ "math.RT" ]
Roger E. Howe
math/9312213
Poisson structures on the cotangent bundle of a Lie group or a principal bundle and their reductions
On a cotangent bundle $T\sp*G$ of a Lie group $G$ one can describe the standard Liouville form $\theta$ and the symplectic form $d \theta$ in terms of the right Maurer Cartan form and the left moment mapping (of the right action of $G$ on itself), and also in terms of the left Maurer-Cartan form and the right moment ma...
1993-12-01
2016-09-06
[ "math.SG", "math.DG" ]
Dmitri V. Alekseevsky, Janusz Grabowski, Giuseppe Marmo, Peter W. Michor
math/9310229
Trace formulae and inverse spectral theory for Schr\"odinger operators
We extend the well-known trace formula for Hill's equation to general one-dimensional Schr\"odinger operators. The new function $\xi$, which we introduce, is used to study absolutely continuous spectrum and inverse problems.
1993-10-01
2008-02-03
[ "math.SP" ]
Fritz Gesztesy, Helge Holden, Barry Simon, Zhong Xin Zhao
math/9307232
Absence of Cantor spectrum for a class of Schr\"odinger operators
It is shown that the complete localization of eigenvectors for the almost Mathieu operator entails the absence of Cantor spectrum for this operator.
1993-07-01
2008-02-03
[ "math.SP", "math.CV" ]
Norbert Riedel
nucl-th/9312022
Dynamical Color Correlations in a $SU(2)_c$ Quark Exchange Model of Nuclear Matter
The quark exchange model is a simple realization of an adiabatic approximation to the strong-coupling limit of Quantum Chromodynamics (QCD): the quarks always coalesce into the lowest energy set of flux tubes. Nuclear matter is thus modeled in terms of its quarks. We wish to study the correlations imposed by total wave...
1993-12-29
2008-11-26
[ "nucl-th", "hep-ph" ]
S. Gardner (Indiana U.), C.J. Horowitz (Indiana U.), and J. Piekarewicz (SCRI)
nucl-th/9312021
Meson phase space density from interferometry
The interferometric analysis of meson correlations provides a measure of the average phase space density of the mesons in the final state. This quantity is a useful indicator of the statistical properties of the system, and it can be extracted with a minimum of model assumptions. Values obtained from recent measurement...
1993-12-28
2009-10-22
[ "nucl-th" ]
George F. Bertsch
nucl-th/9312017
Complex Conjugate Pairs in Stationary Sturmians
Sturmian eigenstates specified by stationary scattering boundary conditions are particularly useful in contexts such as forming simple separable two nucleon t matrices, and are determined via solution of generalised eigenvalue equation using real and symmetric matrices. In general, the spectrum of such an equation may ...
1993-12-22
2008-11-26
[ "nucl-th" ]
P.J.Dortmans, L.Canton, G.Pisent, and K.Amos
nucl-th/9312020
Chaos Driven Decay of Nuclear Giant Resonances: Route to Quantum Self-Organization
The influence of background states with increasing level of complexity on the strength distribution of the isoscalar and isovector giant quadrupole resonance in $^{40}$Ca is studied. It is found that the background characteristics, typical for chaotic systems, strongly affects the fluctuation properties of the strength...
1993-12-22
2009-09-25
[ "nucl-th" ]
S. Drozdz, S. Nishizaki and J. Wambach
nucl-th/9312016
Theory of Coupled Pion--Trinucleon Systems
We derive the dynamical equations which consistently couple the four--body ($\pi$NNN) system to the underlying three--nucleon system. Our treatment can be considered the proper generalization of the Afnan--Blankleider equations for the coupled NN--$\pi$NN system. The resulting connected--kernel equation resembles in st...
1993-12-22
2008-11-26
[ "nucl-th" ]
L. Canton and G. Cattapan
nucl-th/9312018
On the nature of the large-$q$ expansion of the response for a non-relativistic confined system
We show the equivalence of a previously derived exact expression for the response of a non-relativistic system with harmonic forces and an infinite sum of weighted $\delta$-functions corresponding to the spectrum. We forward arguments, indicating that the Gersch-Rodriguez-Smith $1/q$-expansion of the response does not ...
1993-12-22
2009-10-22
[ "nucl-th" ]
E. Pace, G. Salme and A.S. Rinat
nucl-th/9312019
The nuclear component of the EMC effect beyond the Plane Wave Impulse Approximation
We study the response of a nucleus composed of nucleons and confined quarks. Assuming dynamics implied by a non-relativistic cluster model, we prove that the total response is a convolution of the responses of, respectively, a nucleus with interacting point-nucleons and an isolated nucleon with confined quarks. Definin...
1993-12-22
2009-09-25
[ "nucl-th" ]
S. A. Gurvitz and A.S. Rinat
nucl-th/9312015
Semiclassical Quark Model Of the Nuclear Matter Response
The longitudinal response function $R(q,w)$\ of nuclear matter is calculated in a semiclassical quark model. The model has a many- body string-flip potential that confines quarks into hadrons and avoids color van der Waals forces. Molecular dynamics simulations are used to calculate $R(q,w)$\ in one space dimension for...
1993-12-20
2007-05-23
[ "nucl-th" ]
W. Melendez and C. J. Horowitz
nucl-th/9312013
RPA equations and the instantaneous Bethe-Salpeter equation
We give a derivation of the particle-hole RPA equations for an interacting multi-fermion system by applying the instantaneous approximation to the amputated two-fermion propagator of the system. In relativistic field theory the same approximation leads from the fermion-antifermion Bethe-Salpeter equation to the Salpete...
1993-12-20
2008-02-03
[ "nucl-th", "hep-ph" ]
J.Resag, D. Sch\"utte
nucl-th/9312014
On the angular momentum dependence of nuclear level densities
Angular momentum dependence of nuclear level densities at finite temperatures are investigated in the static path approximation(SPA) to the partition function using a cranked quadrupole interaction Hamiltonian in the following three schemes: (i) cranking about x-axis, (ii) cranking about z-axis and (iii) cranking about...
1993-12-19
2009-10-22
[ "nucl-th" ]
B. K. Agrawal and A. Ansari
nucl-th/9312012
S-wave $\pi$-Nucleus Repulsion and Dirac Phenomenology
A relativistic $\pi$-nucleon potential is extended to $m^* \neq m$ to investigate the possibility of generating s-wave $\pi$-nucleus repulsion. We find that relativity does indeed generate significant repulsion, the exact amount depending on the details of the calculation. In contradistinction the $t\rho$ approximation...
1993-12-16
2009-10-22
[ "nucl-th" ]
S. Chakravarti and B.K. Jennings
nucl-th/9312011
Superdeformed rotational bands in the Mercury region; A Cranked Skyrme-Hartree-Fock-Bogoliubov study
A study of rotational properties of the ground superdeformed bands in \Hg{0}, \Hg{2}, \Hg{4}, and \Pb{4} is presented. We use the cranked Hartree-Fock-Bogoliubov method with the {\skm} parametrization of the Skyrme force in the particle-hole channel and a seniority interaction in the pairing channel. An approximate par...
1993-12-13
2015-06-26
[ "nucl-th" ]
B. Gall, P. Bonche, J. Dobaczewski, H. Flocard and P.-H. Heenen
nucl-th/9312010
What can we learn from a second phi meson peak in ultrarelativistic nuclear collisions?
The decay width of a phi meson is reduced from its vacuum value as its mass decreases in hot hadronic matter as a result of the partial restoration of chiral symmetry. This reduction is, however, cancelled by collisional broadening through the reactions $\phi\pi\to KK^*$, $\phi K\to\phi K$, $\phi\rho\to KK$, and $\phi\...
1993-12-10
2009-09-25
[ "nucl-th" ]
Che Ming Ko and David Seibert
nucl-th/9312009
Interference Effects in Relativistic Deuteron Electrodisintegration
We extend the relativistic plane--wave impulse approximation formalism to incorporate a specific class of relativistic interference effects for use in describing inclusive electrodisintegration of $^2$H. The role of these ``exchange'' terms for the various response functions accessible in parity--conserving and --viola...
1993-12-10
2009-10-22
[ "nucl-th" ]
G.I. Poulis (TRIUMF) and T.W. Donnelly (MIT)
nucl-th/9312008
The Multifragmentation Freeze--Out Volume in Heavy Ion Collisions
The reduced velocity correlation function for fragments from the reaction Fe + Au at 100 A~MeV bombarding energy is investigated using the dynamical--statistical approach QMD+SMM and compared to experimental data to extract the Freeze--Out volume assuming simultaneous multifragmentation.
1993-12-09
2009-10-22
[ "nucl-th" ]
G.Peilert, T.C.Sangster, M.N.Namboodiri, and H.C.Britt
nucl-th/9312006
A Quark Model of Lambdabar-Lambda Production of Pbar-P Interactions
A quark model which includes both scalar and vector contributions to the reaction mechanism (SV quark model) is used in a DWBA calculation of $\bar \Lambda \Lambda$ production in $\bar p p$ interractions. Total and differential cross-sections, polarizations, depolarizations, and spin-correlattion coefficients are compu...
1993-12-08
2009-09-25
[ "nucl-th" ]
M.A. Alberg, E.M. Henley, L. Wilets and P.D. Kunz
nucl-th/9312003
Relativistic versus Nonrelativistic Optical Potentials in A(e,e'p)B Reactions
We investigate the role of relativistic and nonrelativistic optical potentials used in the analysis of ($e,e'p$) data. We find that the relativistic calculations produce smaller ($e,e'p$) cross sections even in the case in which both relativistic and nonrelativistic optical potentials fit equally well the elastic proto...
1993-12-07
2009-09-25
[ "nucl-th" ]
J.M. Udias, P. Sarriguren, E. Moya de Guerra, E. Garrido and J.A. Caballero
nucl-th/9312005
Cluster Structure of Disoriented Chiral Condensates in Rapidity Distribution
We study the creation of disoriented chiral condensates with some initial boundary conditions that may be expected in the relativistic heavy ion collisions. The equations of motion in the linear $\sigma$-model are solved numerically with and without a Lorentz-boost invariance. We suggest that a distinct cluster structu...
1993-12-07
2009-12-30
[ "nucl-th", "hep-ph" ]
Zheng Huang and Xin-Nian Wang
nucl-th/9312004
Reply to "Comment on 'Comparison of potential models with the pp-scattering data below 350 MeV.' "
Replying to the above Comment by G.Q.Li and R.Machleidt, we point out that the supposed "flaws" in our Comparison of NN potential models with the pp- scattering data [ Phys.Rev.C47,761(1993) ] are in reality not flaws at all.
1993-12-07
2007-05-23
[ "nucl-th" ]
V.Stoks and J.J. de Swart
nucl-th/9312007
Double Beta Decay in pn-QRPA Model with Isospin and SU(4) Symmetry Constraints
The transition matrix elements for the $0^{+}\to 0^{+}$ double beta decays are calculated for $^{48}Ca$, $^{76}Ge $, $^{82}Se$, $^{100}Mo$, $^{128}Te$ and $^{130}Te$ nuclei, using a ${\delta}$-interaction. As a guide, to fix the particle-particle interaction strengths, we exploit the fact that the missing symmetries of...
1993-12-07
2016-08-14
[ "nucl-th" ]
F. Krmpoti\'c and S. Shelly Sharma
nucl-th/9312001
Comment on "Phase-Shift Analysis of NN Scattering Below 160 Mev: Indication of a Strong Tensor Force"
In his recent publication of a NN phase shift analysis below 160 MeV, Henneck reports relatively large values for the mixing parameter $\epsilon_1$. Based on these results, Henneck suggests that the strength of the $\rho$-meson tensor coupling to the nucleon may be weaker than used in present day NN interactions, like ...
1993-12-01
2009-09-25
[ "nucl-th" ]
G. E. Brown and R. Machleidt
nucl-th/9312002
Relativistic three-particle dynamical equations: II. Application to the trinucleon system
We calculate the contribution of relativistic dynamics on the neutron-deuteron scattering length and triton binding energy employing five sets trinucleon potential models and four types of three-dimensional relativistic three-body equations suggested in the preceding paper. The relativistic correction to binding energy...
1993-12-01
2011-05-12
[ "nucl-th" ]
Sadhan K. Adhikari and Lauro Tomio
nucl-th/9311036
Polarization of the nuclear medium and RPA-type calculations in $K^+$ scattering from nuclei
In the calculation of the $K^+$-nucleus cross sections, the coupling of the mesons exchanged between the $K^+$ and the target nucleons to the polarization of the Fermi sea has been taken into account. This polarization has been calculated in the one-loop approximation but summed up to all orders (RPA-type calculation)....
1993-11-30
2009-10-22
[ "nucl-th" ]
J.C. Caillon and J. Labarsouque
nucl-th/9311035
Relativistic three-particle dynamical equations: I. Theoretical development
Starting from the two-particle Bethe-Salpeter equation in the ladder approximation and integrating over the time component of momentum, we rederive three dimensional scattering integral equations satisfying constraints of relativistic unitarity and covariance, first derived by Weinberg and by Blankenbecler and Sugar. T...
1993-11-29
2009-10-22
[ "nucl-th" ]
Sadhan K. Adhikari, T. Frederico, and Lauro Tomio
nucl-th/9311034
A Model Study of the Strength Distribution for a Collective State Coupled with Chaotic Background System
We consider a model in which a collective state couples to a large number of background states. The background states can be chosen to have properties which are classically characterized as regular or chaotic. We found that the dynamical nature of the background system considerably affects some fluctuation properties o...
1993-11-27
2009-09-25
[ "nucl-th" ]
H.Aiba and T.Suzuki
nucl-th/9311032
The $\pi \sigma$-Axial Exchange Current
The axial exchange current operator that arises from the coupling of the axial field to the pion and effective scalar field in nuclei is constructed. The spatial dependence of this exchange current operator may be determined directly from the nucleon-nucleon interaction. This "$\pi\sigma$"-axial exchange current contri...
1993-11-25
2009-10-22
[ "nucl-th" ]
K. Tsushima and D.O. Riska
nucl-th/9311029
The classification of diagrams in perturbation theory
The derivation of scattering equations connecting the amplitudes obtained from diagrammatic expansions is of interest in many branches of physics. One method for deriving such equations is the classification-of-diagrams technique of Taylor. However, as we shall explain in this paper, there are certain points of Taylor'...
1993-11-25
2009-09-25
[ "nucl-th", "hep-ph" ]
D.R. Phillips and I.R. Afnan
nucl-th/9311033
Shell Effects in Nuclei Near Neutron Drip
Shell effects in nuclei close to the neutron-drip lines have been investigated. It has been demonstrated in the relativistic mean-field theory that nuclei very far from stability manifest the shell effects strongly. This behaviour is in accord with the predictions of nuclear masses in the finite-range droplet model inc...
1993-11-25
2009-10-22
[ "nucl-th" ]
M.M. Sharma, G.A. Lalazissis, W. Hillebrandt, and P.Ring (Max Planck Institut of Astrophysics, and Technical University, Munich)
nucl-th/9311030
Slow proton production in deep-inelastic neutrino scattering on deuterium
The cross section for semi-inclusive deep inelastic charged current neutrino scattering on hydrogen and deuterium in which a slow proton is observed in coincidence with the muon is computed as a function of Bjorken x and light-cone momentum of the detected proton. In the Impulse Approximation contributions from hadroni...
1993-11-25
2016-09-08
[ "nucl-th" ]
G.D. Bosveld, A.E.L. Dieperink and A.G. Tenner
nucl-th/9311031
Microscopic analysis of two-body correlations in light nuclei
Within a nonperturbative dynamical two-body approach - based on coupled equations of motion for the one-body density matrix and the two-body correlation function - we study the distribution of occupation numbers in a correlated system close to the groundstate, the relaxation of single-particle excitations and the dampi...
1993-11-25
2009-10-22
[ "nucl-th" ]
Andreas Peter, Wolfgang Cassing, Joern M. Haeuser and Alfred Pfitzner
nucl-th/9311025
Nuclear Polarization Corrections for the S--Levels of Electronic and Muonic Deuterium
We calculate the second-order corrections to the atomic energy level shifts in ordinary and muonic deuterium due to virtual excitations of the deuteron which are important for ongoing and planned precise experiments in these systems. For light atoms a method can be used in which the shift is expressed as integrals over...
1993-11-24
2009-10-22
[ "nucl-th" ]
Yang Lu and R. Rosenfelder
nucl-th/9311027
Simple approximation for the starting-energy-independent two-body effective interaction with applications to 6Li
We apply the Lee-Suzuki iteration method to calculate the linked-folded diagram series for a new Nijmegen local NN potential. We obtain an exact starting-energy-independent effective two-body interaction for a multi-shell, no-core, harmonic-oscillator model space. It is found that the resulting effective-interaction ma...
1993-11-24
2009-10-22
[ "nucl-th" ]
D.C. Zheng, B.R. Barrett, J.P. Vary and R. J. McCarthy
nucl-th/9311024
Chaotic Dynamics in the Framework of the Vlasov-Nordheim Equation
In the framework of the time-dependent mean field theory, we solve the Vlasov-Nordheim equation and study the sensitive dependence of this highly non-linear equation on the initial conditions. We find that, when nuclear matter is inside the spinodal region, initially small differences between similar trajectories grow ...
1993-11-24
2009-09-25
[ "nucl-th" ]
M. Baldo, G.F. Burgio and A. Rapisarda
nucl-th/9311023
Dilepton production from virtual bremsstrahlung induced by proton capture
Dilepton production following radiative capture of a proton on a nuclear target is studied in the Impulse Approximation. The cross section is decomposed in terms of four time-like nuclear structure functions through a longitudinal-transverse separation of the nuclear current. Using a simple PWIA model, cross sections a...
1993-11-24
2016-09-08
[ "nucl-th" ]
D. Van Neck, A.E.L. Dieperink and O. Scholten
nucl-th/9311026
Nuclear Charge Radii and Electric Quadrupole Moments
Isotope shifts of the mean square radii (MSR) and electric quadrupole moments of even-even nuclei with 20< Z < 98$ are calculated using a dynamical microscopic model. A single particle Nilsson potential with the Seo set of correction term parameters, the pairing forces in the BCS formalism and a long range interaction ...
1993-11-24
2009-09-25
[ "nucl-th" ]
Bozena Nerlo-Pomorska and Beata Mach (UMCS, Lublin, Poland)
nucl-th/9311028
Thermal quark production in ultra-relativistic nuclear collisions
We calculate thermal production of u, d, s, c and b quarks in ultra-relativistic heavy ion collisions. The following processes are taken into account: thermal gluon decay (g to ibar i), gluon fusion (g g to ibar i), and quark-antiquark annihilation (jbar j to ibar i), where i and j represent quark species. We use the t...
1993-11-24
2009-09-25
[ "nucl-th", "hep-ph" ]
Tanguy Altherr and David Seibert (Theory Division, CERN, CH-1211 Geneva 23, Switzerland)
nucl-th/9311020
Coherent Pion Radiation From Nucleon Antinucleon Annihilation
A unified picture of nucleon antinucleon annihilation into pions emerges from a classical description of the pion wave produced in annihilation and the subsequent quantization of that wave as a coherent state. When the constraints of energy-momentum and iso-spin conservation are imposed on the coherent state, the pion ...
1993-11-23
2009-10-22
[ "nucl-th" ]
R. D. Amado, F. Cannata, J. -P. Dedonder, M. P. Locher and Bin Shao
nucl-th/9311021
Rates for the reactions antiproton-proton --> pi phi and gamma phi
We study antiproton-proton annihilation at rest into $\pi\phi$ and $\gamma\phi$. Rescattering by $\overline{K^*}K+K^*\overline{K}$ and $\rho^{+}\rho^{-}$ for $\overline{p}p\rightarrow\pi\phi$ states is sizable, of order $(0.90\, {\rm to}\,2.6)\times 10^{-4}$ in the branching ratio, but smaller than experiment. For $\ov...
1993-11-23
2015-06-26
[ "nucl-th" ]
M.P. Locher, Y. Lu and B.S. Zou
nucl-th/9311022
Three-body resonances by complex scaling
It is demonstrated that the complex scaling method can be used in practical calculations to localize three-body resonances. Our model example emphasizes the fact that in three-body systems several essentially different asymptotic behaviors can appear. We show that the possibility of these different asymptotic configura...
1993-11-23
2009-09-25
[ "nucl-th" ]
Attila Csoto
nucl-th/9311019
Optical-Model Description of Time-Reversal Violation
A time-reversal-violating spin-correlation coefficient in the total cross section for polarized neutrons incident on a tensor rank-2 polarized target is calculated by assuming a time-reversal-noninvariant, parity-conserving ``five-fold" interaction in the neutron-nucleus optical potential. Results are presented for the...
1993-11-22
2009-09-25
[ "nucl-th" ]
V. Hnizdo and C. R. Gould (TUNL)
nucl-th/9311018
Pion Properties in a Hot $\Pi N \Delta$ Gas
Based on a recent meson-exchange model for the vacuum $\pi\pi$ interaction we compute selfconsistently the in-medium $\pi\pi$ scattering amplitude and pion selfenergy in a hot $\pi N\Delta$ gas. The contributions to the pion selfenergy are calculated from the $\pi\pi$ T-matrix as well as from p-wave interaction with nu...
1993-11-20
2010-11-01
[ "nucl-th" ]
R. Rapp and J. Wambach
nucl-th/9311017
On Size and Shape of the Average Meson Fields in the Semibosonized Nambu & Jona-Lasinio Model
We consider a two-flavor Nambu \& Jona-Lasinio model in Hartree approximation involving scalar-isoscalar and pseudoscalar-isovector quark-quark interactions. Average meson fields are defined by minimizing the effective Euklidean action. The fermionic part of the action, which contains the full Dirac sea, is regularized...
1993-11-19
2015-06-26
[ "nucl-th" ]
R.Wuensch, K.Goeke, Th.Meissner
nucl-th/9311016
Higher-shell corrections for systems with one and two valence nucleons: A spin-orbit and tensor interaction analysis
It is shown that when higher-shell admixtures are included for systems with two valence particles or holes, there are effects which are quite different from those for one-valence-nucleon systems. For example, for nuclei with one valence particle or hole, there is no first-order correction for the magnetic dipole moment...
1993-11-19
2009-09-25
[ "nucl-th" ]
D.C. Zheng, L. Zamick and M. Fayache
nucl-th/9311015
Inclusive Quasielastic and Deep Inelastic Scattering of Polarized Electrons by Polarized $^{3}$He}
A comprehensive treatement of the theoretical approach for describing nuclear effects in inclusive scattering of polarized electrons by polarized $^3$He is presented.
1993-11-17
2009-09-25
[ "nucl-th" ]
C. Ciofi degli Atti, S. Scopetta, E. Pace, G. Salm\`e
nucl-th/9311014
Semiclassical Analysis of the Supershell Effect in Reflection-Asymmetric Superdeformed Oscillator
An oscillatory pattern in the smoothed quantum spectrum, which is unique for single-particle motions in a reflection-asymmetric superdeformed oscillator potential, is investigated by means of the semiclassical theory of shell structure. Clear correspondence between the oscillating components of the smoothed level densi...
1993-11-15
2017-02-01
[ "nucl-th" ]
Ken-ichiro Arita and Kenichi Matsuyanagi (Kyoto Univ.)
nucl-th/9311013
Electromagnetic Gauge Invariance of Chiral Hybrid Quark Models
In this work, we investigate the question, whether the conventional analysis of the electromagnetic form factors of the nucleon, evaluated in the framework of the cloudy bag model (CBM) or other chirally invariant hybrid quark models utilizing the same philosophy, is gauge invariant. In order to address that point, we ...
1993-11-13
2008-11-26
[ "nucl-th" ]
W. Koepf and E.M. Henley
nucl-th/9311012
Constraints on the $\pi NN$ Coupling Constant from the $NN$ System
The sensitivity of the deuteron and of $pp$ scattering to the $\pi NN$ and $\rho NN$ coupling constants is investigated systematically. We find that the deuteron can be described about equally well with either {\it large $\pi$ and $\rho$} or {\it small $\pi$ and $\rho$} coupling constants. However, $pp$ scattering clea...
1993-11-11
2009-09-25
[ "nucl-th" ]
R. Machleidt and G. Q. Li (University of Idaho)
nucl-th/9311011
Deformed Gaussian Orthogonal Ensemble Analysis of the Interacting Boson Model
A Deformed Gaussian Orthogonal Ensemble (DGOE) which interpolates between the Gaussian Orthogonal Ensemble and a Poissonian Ensemble is constructed. This new ensemble is then applied to the analysis of the chaotic properties of the low lying collective states of nuclei described by the Interacting Boson Model (IBM). Th...
1993-11-11
2009-09-25
[ "nucl-th" ]
M.P. Pato, C.A. Nunes, C.L. Lima, M.S. Hussein, Y. Alhassid
nucl-th/9311010
Exact, finite, and Hermitian fermion-pair-to-boson mapping
We discuss a general, exact (in that matrix elements are preserved) mapping of fermion pairs to bosons, and find a simple factorization of the boson representation of fermion operators. This leads to boson Hamiltonians that are Hermitian and finite, with no more than two-body operators if the fermion Hamiltonian has at...
1993-11-10
2007-05-23
[ "nucl-th" ]
Calvin W. Johnson and Joseph N. Ginocchio
nucl-th/9311008
Deep Inelastic Scattering from off-Shell Nucleons
We derive the general structure of the hadronic tensor required to describe deep-inelastic scattering from an off-shell nucleon within a covariant formalism. Of the large number of possible off-shell structure functions we find that only three contribute in the Bjorken limit. In our approach the usual ambiguities encou...
1993-11-09
2009-09-25
[ "nucl-th", "hep-ph" ]
W.Melnitchouk (Regensburg), A.W.Schreiber (PSI) and A.W.Thomas (Adelaide)
nucl-th/9311007
Nuclear shell-model calculations for 6Li and 14N with different NN potentials
Two ``phase-shift equivalent'' local NN potentials with different parametrizations, Reid93 and NijmII, which were found to give nearly identical results for the triton by Friar et al, are shown to yield remarkably similar results for 6Li and 14N in a (0+2)hw no-core space shell-model calculation. The results are compar...
1993-11-09
2009-09-25
[ "nucl-th" ]
D. C. Zheng and B. R. Barrett
nucl-th/9311009
A Systematic Treatment of Triaxial Systems at High Spins. II
The BRST treatment of triaxial nuclei rotating at high spins, which had been previously developed, is extended to relate states with neighboring values of the angular momentum $I$. As a consequence, the irreducible multipole transition operators can be unambiguously separated into their physical and spurious components...
1993-11-09
2009-10-22
[ "nucl-th" ]
J. P. Garrahan and D. R. Bes
nucl-th/9311006
Is Schr\"{o}dinger's Conjecture for the Hydrogen Atom Coherent States Attainable
We construct the most general SO(4,2) hydrogen atom coherent states which are the counterpart of Schr\"{o}dinger's harmonic oscillator coherent states. We show that these states cannot be localized and cannot follow the classical orbits. Thus, Schr\"{o}dinger's conjecture for the hydrogen atom coherent states is unatta...
1993-11-08
2009-10-22
[ "nucl-th", "chao-dyn", "nlin.CD" ]
Ivaylo Zlatev, Wei-Min Zhang and Da Hsuan Feng
nucl-th/9311005
Medium Modification to the $\Omega$-Meson Mass in the Walecka Model
We calculate the effective mass of the $\omega$ meson in nuclear matter in a relativistic random-phase approximation to the Walecka model. The dressing of the meson propagator is driven by its coupling to particle-hole pairs and nucleon-antinucleon ($N\bar{N}$) excitations. We report a reduction in the $\omega$-meson m...
1993-11-05
2009-09-25
[ "nucl-th" ]
H.-C. Jean, J. Piekarewicz and A. G. Williams
nucl-th/9311004
E2 properties of nuclei far from stability and the proton-halo problem of 8B
E2 properties of A=6--10 nuclei, including those of nuclei far from stability, are studied by a $(0+2)\hbar\omega$ shell-model calculation which includes E2 core-polarization effects explicitly. The quadrupole moments and the E2 transition strengths in A=6--10 nuclei are described quite well by the present calculation....
1993-11-04
2009-10-22
[ "nucl-th" ]
Hitoshi Nakada and Takaharu Otsuka
nucl-th/9311003
Two pion bound states in a hot pion gas
The occurrence of poles in the $2\pi$ propagator in a hot pion medium is studied. The domain of non--trivial solutions to the corresponding bosonic gap equation is investigated as a function of the chemical potential and temperature of the gas.
1993-11-03
2007-05-23
[ "nucl-th" ]
G. Chanfray, P. Schuck, and G. Welke
nucl-th/9311002
Spectral asymmetries in nucleon sum rules at finite density
Apparent inconsistencies between different formulations of nucleon sum rules at finite density are resolved through a proper accounting of asymmetries in the spectral functions between positive- and negative-energy states.
1993-11-03
2008-11-26
[ "nucl-th", "hep-ph" ]
R. J. Furnstahl