id
large_stringlengths
9
16
title
large_stringlengths
1
382
abstract
large_stringlengths
3
6.09k
publish_date
date32
update_date
date32
categories
large listlengths
1
13
authors
large_stringlengths
3
62.8k
cs/9402102
Substructure Discovery Using Minimum Description Length and Background Knowledge
The ability to identify interesting and repetitive substructures is an essential component to discovering knowledge in structural data. We describe a new version of our SUBDUE substructure discovery system based on the minimum description length principle. The SUBDUE system discovers substructures that compress the ori...
1994-02-01
2008-02-03
[ "cs.AI" ]
D. J. Cook, L. B. Holder
cs/9402103
Bias-Driven Revision of Logical Domain Theories
The theory revision problem is the problem of how best to go about revising a deficient domain theory using information contained in examples that expose inaccuracies. In this paper we present our approach to the theory revision problem for propositional domain theories. The approach described here, called PTR, uses pr...
1994-02-01
2014-11-17
[ "cs.AI" ]
M. Koppel, R. Feldman, A. M. Segre
cs/9401101
Teleo-Reactive Programs for Agent Control
A formalism is presented for computing and organizing actions for autonomous agents in dynamic environments. We introduce the notion of teleo-reactive (T-R) programs whose execution entails the construction of circuitry for the continuous computation of the parameters and conditions on which agent action is based. In a...
1994-01-01
2014-11-17
[ "cs.AI" ]
N. Nilsson
cs/9401102
Mini-indexes for literate programs
This paper describes how to implement a documentation technique that helps readers to understand large programs or collections of programs, by providing local indexes to all identifiers that are visible on every two-page spread. A detailed example is given for a program that finds all Hamiltonian circuits in an undirec...
1994-01-01
2008-02-03
[ "cs.PL" ]
Donald E. Knuth
dg-ga/9412007
Meromorphic Potentials and Smooth CMC Surfaces
This work is based on the approach developed by J.~Dorfmeister, F.~Pedit and H.~Wu [GANG and KITCS preprint, Report KITCS94-4-1] to construct maps $\Phi:D\rightarrow R^3$, $D$ being the unit disk in $C$, whose images are surfaces of constant mean curvature. They start from certain meromorphic one forms, so called merom...
1994-12-31
2008-02-03
[ "dg-ga", "math.DG" ]
J. Dorfmeister, G. Haak
dg-ga/9412006
On the Scalar Curvature of Complex Surfaces
Let (M,J) be a minimal compact complex surface of Kaehler type. It is shown that the smooth 4-manifold M admits a Riemannian metric of positive scalar curvature iff (M,J) admits a KAEHLER metric of positive scalar curvature. This extends previous results of Witten and Kronheimer.
1994-12-27
2008-02-03
[ "dg-ga", "math.DG" ]
Claude LeBrun
dg-ga/9412004
Blow-up formulas for (-2)-spheres
Let $X$ be a simply connected 4-manifold containing a $(-1)$-sphere $e$. Fintushel and Stern prove that $$ D_c(\exp(te)) = D_c(B(t)) on e^\perp if c\cdot e is even, $$ $$ D_c(\exp(te)) = D_{c-e}(S(t)) on e^\perp if c \cdot e is odd, $$ for some universal series $B(t),S(t) \in \Q[x][[t]]$ with $x$ the class of a point. ...
1994-12-23
2008-02-03
[ "dg-ga", "math.DG" ]
Rogier Brussee
dg-ga/9412005
Symplectic toric orbifolds
A symplectic toric orbifold is a compact connected orbifold $M$, a symplectic form $\omega$ on $M$, and an effective Hamiltonian action of a torus $T$ on $M$, where the dimension of $T$ is half the dimension of $M$. We prove that there is a one-to-one correspondence between symplectic toric orbifolds and convex rationa...
1994-12-23
2008-02-03
[ "dg-ga", "math.DG" ]
Eugene Lerman (M.I.T.) and Susan Tolman (M.I.T.)
dg-ga/9412003
Symplectic and Poisson structures of certain moduli spaces. II. Projective representations of cocompact discrete planar groups
Let $G$ be a Lie group with a biinvariant metric, not necessarily positive definite. It is shown that a certain construction carried out in an earlier paper for the fundamental group of a closed surface may be extended to an arbitrary infinite orientation preserving cocompact planar discrete group of euclidean or non-e...
1994-12-21
2008-02-03
[ "dg-ga", "math.DG" ]
Johannes Huebschmann (Max Planck I. f. Math., Bonn)
dg-ga/9412002
Differential Geometry of Composite Fibred Manifolds
In classical field theory, the composite fibred manifolds Y -> Z -> X provides the adequate mathematical formulation of gauge models with broken symmetries, e.g., the gauge gravitation theory. This work is devoted to connections on composite fibred manifolds. In particular, we get the horizontal splitting of the vertic...
1994-12-17
2008-02-03
[ "dg-ga", "math.DG" ]
G.Sardanashvily (Moscow State University)
dg-ga/9412001
Nowhere Holomorphic Mappings
Retracted temporarily to fix some erratic things.
1994-12-15
2008-02-03
[ "dg-ga", "math.DG" ]
Yuliy Baryshnikov
dg-ga/9411014
Smoothing Riemannian Metrics with Ricci Curvature Bounds
We prove that Riemannian metrics with an absolute Ricci curvature bound and a conjugate radius bound can be smoothed to having a sectional curvature bound. Using this we derive a number of results about structures of manifolds with Ricci curvature bounds.
1994-11-30
2008-02-03
[ "dg-ga", "math.DG" ]
Xianzhe Dai, Guofang Wei and Rugang Ye
dg-ga/9411015
Integral geometry of plane curves and knot invariants
We study the integral expression of a knot invariant obtained as the second coefficient in the perturbative expansion of Witten's Chern-Simons path integral associated with a knot. One of the integrals involved turns out to be a generalization of the classical Crofton integral on convex plane curves and it is related w...
1994-11-30
2008-02-03
[ "dg-ga", "hep-th", "math.DG" ]
Xiao-Song Lin and Zhenghan Wang
dg-ga/9411013
Witten deformation of the analytic torsion and the spectral sequence of a filtration
Let F be a flat vector bundle over a compact Riemannian manifold M and let f be a Morse function. Let g be a smooth Euclidean metric on F, let g_t=e^{-2tf}g and let \rho(t) be the Ray-Singer analytic torsion of F associated to the metric g_t. Assuming that the vector field grad(f) satisfies the Morse-Smale transversali...
1994-11-27
2008-02-03
[ "dg-ga", "hep-th", "math.DG" ]
Maxim Braverman
dg-ga/9411012
Pseudoconvex and Disprisoning Homogeneous Sprays
The pseudoconvex and disprisoning conditions for geodesics of linear connections are extended to the solution curves of general homogeneous sprays. The main result is that pseudoconvexity and disprisonment are jointly stable in the fine topology on the space of all homogeneous sprays of any degree of homogeneity.
1994-11-26
2008-02-03
[ "dg-ga", "math.DG" ]
L. Del Riego and P.E. Parker
dg-ga/9411008
Smooth structures on certain moduli spaces for bundles on a surface
Let $\Sigma$ be a closed surface, $G$ a compact Lie group, with Lie algebra $g$, $\xi \colon P \to \Sigma$ a principal $G$-bundle, let $N(\xi)$ denote the moduli space of central Yang-Mills connections on $\xi$, for suitably chosen additional data, and let $\roman{Rep}_{\xi}(\Gamma,G)$ be the space of representations o...
1994-11-23
2008-02-03
[ "dg-ga", "math.DG" ]
Johannes Huebschmann (Max Planck I. f. Math., Bonn)
dg-ga/9411011
The number of functionally independent invariants of a pseudo--Riemannian metric
The number of functionally independent scalar invariants of arbitrary order of a generic pseudo--Riemannian metric on an $n$--dimensional manifold is determined.
1994-11-23
2009-10-22
[ "dg-ga", "gr-qc", "math.DG" ]
J Mu\~noz Masqu\'e and Antonio Vald\'es
dg-ga/9411009
Poisson structures on certain moduli spaces for bundles on a surface
Let $\Sigma$ be a closed surface, $G$ a compact Lie group, with Lie algebra $g$, and $\xi \colon P \to \Sigma$ a principal $G$-bundle. In earlier work we have shown that the moduli space $N(\xi)$ of central Yang- Mills connections, for appropriate additional data, is stratified by smooth symplectic manifolds and that t...
1994-11-23
2008-02-03
[ "dg-ga", "math.DG" ]
Johannes Huebschmann (Max Planck I. f. Math., Bonn)
dg-ga/9411010
Curved Flats and Isothermic Surfaces
We show how pairs of isothermic surfaces are given by curved flats in a pseudo Riemannian symmetric space and vice versa. Calapso's fourth order partial differential equation is derived and, using a solution of this equation, a M\"obius invariant frame for an isothermic surface is built.
1994-11-23
2008-02-03
[ "dg-ga", "math.DG" ]
F. Burstall, U. Hertrich-Jeromin, F. Pedit and U. Pinkall
dg-ga/9411006
The singularities of Yang-Mills connections for bundles on a surface. I. The local model
Let $\Sigma$ be a closed surface, $G$ a compact Lie group, not necessarily connected, with Lie algebra $g$, endowed with an adjoint action invariant scalar product, let $\xi \colon P \to \Sigma$ be a principal $G$-bundle, and pick a Riemannian metric and orientation on $\Sigma$, so that the corresponding Yang-Mills equ...
1994-11-22
2008-02-03
[ "dg-ga", "math.DG" ]
Johannes Huebschmann (Max Planck I. f. Math., Bonn)
dg-ga/9411007
The singularities of Yang-Mills connections for bundles on a surface. II. The stratification
Let $\Sigma$ be a closed surface, $G$ a compact Lie group, not necessarily connected, with Lie algebra $g$, endowed with an adjoint action invariant scalar product, let $\xi \colon P \to \Sigma$ be a principal $G$-bundle, and pick a Riemannian metric and orientation on $\Sigma$ so that the corresponding Yang-Mills equa...
1994-11-22
2008-02-03
[ "dg-ga", "math.DG" ]
Johannes Huebschmann (Max Planck I. f. Math., Bonn)
dg-ga/9411005
Einstein Metrics and Mostow Rigidity
Using the new diffeomorphism invariants of Seiberg and Witten, a uniqueness theorem is proved for Einstein metrics on compact quotients of irreducible 4-dimensional symmetric spaces of non-compact type. The proof also yields a Riemannian version of the Miyaoka-Yau inequality.
1994-11-21
2008-02-03
[ "dg-ga", "math.DG" ]
Claude LeBrun
dg-ga/9411004
$\Gamma$-Cohomology and the Selberg Zeta Function
We propose a new method for studying $n$- and $\Gamma$-cohomology of globalizations of Harish-Chandra modules, where $G=KAN$ is a rank one semisimple Lie group, $\Gamma$ is a discrete subgroup of $G$ and $n=Lie(N)$. We prove a conjecture of Patterson relating the singularities of Selberg zeta functions with the $\Gamma...
1994-11-18
2008-02-03
[ "dg-ga", "math.DG" ]
Ulrich Bunke, Martin Olbrich
dg-ga/9411002
Yamabe Spectra
We study the set of volumes of constant scalar curvature one metrics on an atoroidal three-manifold.The infinum of this set is believed to be attained at a hyperbolic metric. We prove that the supremum of this set is always infinity. The technique is: minimal surfaces, Thurston norm in homology and new conformal invari...
1994-11-07
2016-08-31
[ "dg-ga", "math.DG" ]
Alexander Reznikov
dg-ga/9411003
Ricci Curvature and Betti Numbers
We derive a uniform bound for the total betti number of a closed manifold in terms of a Ricci curvature lower bound, a conjugate radius lower bound and a diameter upper bound. The result is based on an angle version of Toponogov comparison estimate for small triangles in a complete manifold with a Ricci curvature lower...
1994-11-07
2008-02-03
[ "dg-ga", "math.DG" ]
Guofang Wei
dg-ga/9411001
Self-Dual Manifolds with Positive Ricci Curvature
We prove that the connected sums CP_2 # CP_2 and CP_2 # CP_2 # CP_2 admit self-dual metrics with positive Ricci curvature. Moreover, every self-dual metric of positive scalar curvature on CP_2 # CP_2 is conformal to a metric with positive Ricci curvature.
1994-11-04
2008-02-03
[ "dg-ga", "math.DG" ]
Claude LeBrun, Shin Nayatani, and Takashi Nitta
dg-ga/9410007
The Fr\"olicher-Nijenhuis bracket for derivation based non commutative differential forms
In commutative differential geometry the Fr\"olicher-Nijenhuis bracket computes all kinds of curvatures and obstructions to integrability. In \cit!{3} the Fr\"olicher-Nijenhuis bracket was developped for universal differential forms of non-commutative algebras, and several applications were given. In this paper this br...
1994-10-19
2008-02-03
[ "dg-ga", "math.DG" ]
Michel Dubois-Violette, Peter W. Michor
dg-ga/9410006
Geometry of Cyclic Quotients, I: Knotted Totally Geodesic Submanifolds in Positively Curved Spheres
We prove that there exists a metric of positive curvature in a three-sphere which admits a given torus knot as a closed geodesic.We also sketch a construction of a metric in a four sphere, very likely of positive curvature, which admits a totally geodesic projective plane with Euler number four. Surpisingly, the techni...
1994-10-16
2008-02-03
[ "dg-ga", "math.DG" ]
Alexander Reznikov
dg-ga/9410005
Hermitian structures and harmonic morphisms in higher dimensional Euclidean spaces
We construct new complex-valued harmonic morphisms from Euclidean spaces from functions which are holomorphic with respect to Hermitian structures. In particular, we give the first global examples of complex-valued harmonic morphisms from ${\bf R}^n$ for each $n>4$ which do not arise from a K\"ahler structure; it is kn...
1994-10-13
2008-02-03
[ "dg-ga", "math.DG" ]
P. Baird and J.C. Wood
dg-ga/9410004
A construction of singular solutions for a semilinear elliptic equation using asymptotic analysis
The aim of this paper is to prove the existence of weak solutions to the equation $\Delta u + u^p = 0$ which are positive in a domain $\Omega \subset {\Bbb R}^N$, vanish at the boundary, and have prescribed isolated singularities. The exponent $p$ is required to lie in the interval $(N/(N-2), (N+2)/(N-2))$. We also pro...
1994-10-10
2016-08-31
[ "dg-ga", "math.DG" ]
Rafe Mazzeo (Stanford), Frank Pacard (ENPC-Cergrene)
dg-ga/9410003
On Rumin's Complex and Adiabatic Limits
This paper shows that when the Riemannian metric on a contact manifold is blown up along the direction orthogonal to the contact distribution, the corresponding harmonic forms rescaled and normalized in the $L^2$-norms will converge to Rumin's harmonic forms. This proves a conjecture in Gromov `` Carnot-Caratheodory sp...
1994-10-05
2008-02-03
[ "dg-ga", "math.DG" ]
Zhong Ge
dg-ga/9410002
3-manifolds with(out) metrics of nonpositive curvature
In the context of Thurstons geometrisation program we address the question which compact aspherical 3-manifolds admit Riemannian metrics of nonpositive curvature. We show that non-geometric Haken manifolds generically, but not always, admit such metrics. More precisely, we prove that a Haken manifold with, possibly emp...
1994-10-04
2009-10-22
[ "dg-ga", "math.DG" ]
Bernhard Leeb
dg-ga/9410001
Dressing orbits of harmonic maps
We study the harmonic map equations for maps of a Riemann surface into a Riemannian symmetric space of compact type from the point of view of soliton theory. There is a well-known dressing action of a loop group on the space of harmonic maps and we discuss the orbits of this action through particularly simple harmonic ...
1994-10-04
2008-02-03
[ "dg-ga", "math.DG" ]
F.E. Burstall and F. Pedit
dg-ga/9409005
On multilinear operators commuting with Lie derivatives
Let $E_1,\dots ,E_k$ and $E$ be natural vector bundles defined over the category $\Cal Mf_m^+$ of smooth oriented $m$--dimensional manifolds and orientation preserving local diffeomorphisms, with $m\geq 2$. Let $M$ be an object of $\Cal Mf_m^+$ which is connected. We give a complete classification of all separately con...
1994-09-28
2016-08-31
[ "dg-ga", "math.DG" ]
Andreas Cap, Jan Slovak
dg-ga/9409004
On the nonHamiltonian interaction of two rotators
Classical dynamical equations describing a certain version of the nonHamiltonian interaction of two rotators (Euler tops with completely degenerate inertia tensors) are considered. The simplest case is integrated. It is shown that the dynamics is almost periodic with periods depending on the initial data.
1994-09-23
2008-02-03
[ "dg-ga", "chao-dyn", "math.DG", "nlin.CD", "nlin.SI", "solv-int" ]
Denis V. Juriev
dg-ga/9409003
The spectrum of an asymptotically hyperbolic Einstein manifold
This paper relates the spectrum of the scalar Laplacian of an asymptotically hyperbolic Einstein metric to the conformal geometry of its ``ideal boundary'' at infinity. It follows from work of R. Mazzeo that the essential spectrum of such a metric on an $(n+1)$-dimensional manifold is the ray $[n^2/4,\infty)$, with no ...
1994-09-19
2008-02-03
[ "dg-ga", "math.DG" ]
John M. Lee (University of Washington)
dg-ga/9409002
Scalar-Flat Kaehler Surfaces of All Genera
Let (M,J) be a compact complex 2-manifold which which admits a Kaehler metric for which the integral of the scalar curvature is non-negative. Also suppose that M does not admit a Ricci-flat K\"ahler metric. Then if M is blown up at sufficiently many points, the resulting complex surface admits Kaehler metrics with scal...
1994-09-09
2008-02-03
[ "dg-ga", "math.DG" ]
Jongsu Kim, Claude LeBrun, and Massimiliano Pontecorvo
dg-ga/9409001
Fano Manifolds, Contact Structures, and Quaternionic Geometry
Let Z be a compact complex (2n+1)-manifold which carries a {\em complex contact structure}, meaning a codimension-1 holomorphic sub-bundle D of TZ which is maximally non-integrable. If Z admits a K\"ahler-Einstein metric of positive scalar curvature, we show that it is the Salamon twistor space of a quaternion-K\"ahler...
1994-09-09
2008-02-03
[ "dg-ga", "math.DG" ]
Claude LeBrun
dg-ga/9408005
On the Dirichlet problem for harmonic maps with prescribed singularities
Let $\M$ be a classical Riemannian globally symmetric space of rank one and non-compact type. We prove the existence and uniqueness of solutions to the Dirichlet problem for harmonic maps into $\M$ with prescribed singularities along a closed submanifold of the domain. This generalizes our previous work where such maps...
1994-08-26
2010-06-24
[ "dg-ga", "math.DG" ]
Gilbert Weinstein
dg-ga/9408004
The Moduli Space of Complete Embedded Constant Mean Curvature Surfaces
We examine the space of surfaces in $\RR^{3}$ which are complete, properly embedded and have nonzero constant mean curvature. These surfaces are noncompact provided we exclude the case of the round sphere. We prove that the space $\Mk$ of all such surfaces with $k$ ends (where surfaces are identified if they differ by ...
1994-08-19
2008-02-03
[ "dg-ga", "math.DG" ]
Rob Kusner, Rafe Mazzeo and Daniel Pollack
dg-ga/9408003
Modular operads
Modular operads are a special type of operad: in fact, they bear the same relationship to operads that graphs do to trees (i.e. simply connected graphs). One of the basic examples of a modular operad is the collection of Deligne-Mumford-Knudsen moduli spaces $\bar{M}_{g,n}$ of stable pointed algebraic curves; hence the...
1994-08-17
2009-09-25
[ "dg-ga", "alg-geom", "hep-th", "math.AG", "math.DG" ]
E. Getzler and M.M. Kapranov (Departments of Mathematics, MIT and Northwestern University)
dg-ga/9408002
Witten deformation of Ray-Singer analytic torsion
Consider a flat vector bundle F over compact Riemannian manifold M and let f be a self-indexing Morse function on M. Let g be a smooth Euclidean metric on F. Set g_t=exp(-2tf)g and let \rho(t) be the Ray-Singer analytic torsion of F associated to the metric g_t. Assuming that the vector field $grad f$ satisfies the Mor...
1994-08-16
2016-08-31
[ "dg-ga", "hep-th", "math.DG" ]
Maxim Braverman
dg-ga/9408001
Convexity Properties of the Moment Mapping Re-examined
Consider a Hamiltonian action of a compact Lie group on a compact symplectic manifold. A theorem of Kirwan's says that the image of the momentum mapping intersects the positive Weyl chamber in a convex polytope. I present a new proof of Kirwan's theorem, which gives explicit information on how the vertices of the polyt...
1994-08-15
2008-02-03
[ "dg-ga", "alg-geom", "math.AG", "math.DG" ]
Reyer Sjamaar
dg-ga/9407015
Bundle gerbes
Just as $\Cstar$ principal bundles provide a geometric realisation of two-dimensional integral cohomology; gerbes or sheaves of groupoids, provide a geometric realisation of three dimensional integral cohomology through their Dixmier-Douady class. I consider an alternative, related, geometric realisation of three dimen...
1994-07-25
2008-02-03
[ "dg-ga", "math.DG" ]
Michael K. Murray
dg-ga/9407013
Theta and zeta functions for locally symmetric spaces of rank one
We study the Selberg zeta and the theta function associated to bundles over even-dimensional locally symmetric spaces of rank one.
1994-07-22
2008-02-03
[ "dg-ga", "math.DG" ]
Ulrich Bunke and Martin Olbrich
dg-ga/9407014
A theta function for hyperbolic surfaces with cusps
For a Riemann surface with cusps we define a theta function using the eigenvalues of the Laplacian and the singularities of the scattering determinant. We provide its meromorphic continuation and discuss its singularities.
1994-07-22
2008-02-03
[ "dg-ga", "math.DG" ]
Ulrich Bunke and Martin Olbrich
dg-ga/9407012
Theta and zeta functions for odd-dimensional locally symmetric spaces of rank one
This paper is a continuation of our work on theta and zeta functions In the previous papers we considered the case of even dimensional rank one symmetric spaces of non-compact type. The present is concerned with the odd-dimensional case, i.e. with odd-dimensional real hyperbolic manifolds. It is the natural appearence ...
1994-07-22
2008-02-03
[ "dg-ga", "math.DG" ]
Ulrich Bunke and Martin Olbrich
dg-ga/9407011
Pr\'equantification de Certaines Vari\'et\'es de Poisson
A surjective submersion $\pi : M \to B$ carrying a field of simplectic structures on the fibres is symplectic if this Poisson structure is minimal. A symplectic submersion may be interpreted as a family of mechanical systems depending on a parameter in $B$. We give some conditions to find a closed form which represent ...
1994-07-21
2008-02-03
[ "dg-ga", "math.DG" ]
F. Alcalde Cuesta
dg-ga/9407010
Quadratic Equations in Groups from the Global Geometry Viewpoint
I use harmonic maps and minimal surfaces to study quadratic equations in groups.
1994-07-21
2008-02-03
[ "dg-ga", "math.DG" ]
Alexander Reznikov
dg-ga/9407009
Int\'egration symplectique des vari\'et\'es de Poisson r\'eguli\`eres
A symplectic integration of a Poisson manifold $(M,\Lambda)$ is a symplectic groupoid $(\Gamma,\eta)$ which realizes the given Poisson manifold, i.e. such that the space of units $\Gamma_0$ with the induced Poisson structure $\Lambda_0$ is isomorphic to $(M,\Lambda)$. This notion was introduced by A. Weinstein in order...
1994-07-20
2008-02-03
[ "dg-ga", "math.DG" ]
F. Alcalde-Cuesta, G. Hector
dg-ga/9407008
Jumps of the eta invariant
We study the eta-invariant, defined by Atiyah-Patodi-Singer a real valued invariant of an oriented odd-dimensional Riemannian manifold equipped with a unitary representation of its fundamental group. When the representation varies analytically, the corresponding eta-invariant may have an integral jump, known also as th...
1994-07-20
2008-02-03
[ "dg-ga", "math.DG" ]
Michael S. Farber, Jerome P. Levine
dg-ga/9407007
Rationality of secondary classes
We prove the Bloch conjecture : $ c_2(E) \in H^4_\cald (X,\bbz(2))$ is torsion for holomorphic rank two vector bundles $E$ with an integrable connection over a complex projective variety $X$. We prove also the rationality of the Chern-Simons invariant of compact arithmetic hyperbolic three-manifolds. We give a sharp hi...
1994-07-19
2008-02-03
[ "dg-ga", "math.DG" ]
Alexander Reznikov
dg-ga/9407006
All regulators of flat bundles are torsion
I prove the Bloch conjecture:all secondary characteristic classes of flat bundles over complex projective varietes are torsion, except the first.
1994-07-18
2008-02-03
[ "dg-ga", "math.DG" ]
Alexander Reznikov
dg-ga/9407004
Transformation de Fourier-Mukai sur les Surfaces Hyperk\"ahl\'eriennes
Given two compact hyperk\"ahler surfaces $X$ and $Y$ and a holomorphic vector bundle $Q$ on $X\times Y$, which is a generalized instanton, one can define a Fourier-Mukai transform, which, under suitable assumptions, maps vector bundles on $X$ to vector bundles on $Y$. If $X$ and $Y$ are dual complex tori, this transfor...
1994-07-15
2008-02-03
[ "dg-ga", "math.DG" ]
C. Bartocci, U. Bruzzo and D. Hernandez Ruiperez
dg-ga/9407005
A note on the index bundle over the moduli space of monopoles
Donaldson has shown that the moduli space of monopoles $M_k$ is diffeomorphic to the space $\Rat_k$ of based rational maps from the two-sphere to itself. We use this diffeomorphism to give an explicit description of the bundle on $\Rat_k$ obtained by pushing out the index bundle from $M_k$. This gives an alternative an...
1994-07-15
2009-10-22
[ "dg-ga", "hep-th", "math.DG" ]
John D. S. Jones and Michael K. Murray
dg-ga/9407003
Proper group actions and symplectic stratified spaces
Let $(M,\omega)$ be a Hamiltonian $G$-space with a momentum map $F:M \to {\frak g}^*$. It is well-known that if $\alpha$ is a regular value of $F$ and $G$ acts freely and properly on the level set $F^{-1}(G\cdot \alpha)$, then the reduced space $M_\alpha :=F^{-1}(G\cdot \alpha)/G$ is a symplectic manifold. We show that...
1994-07-07
2008-02-03
[ "dg-ga", "math.DG" ]
L. Bates and E. Lerman
dg-ga/9407002
A ``stable'' version of the Gromov-Lawson conjecture
We discuss a conjecture of Gromov and Lawson, later modified by Rosenberg, concerning the existence of metrics of positive scalar curvature. It says that a closed spin manifold $M$ of dimension $n\ge 5$ has such a metric if and only if the index of a suitable ``Dirac" operator in $KO_n(C^* (\pi_1(M)))$, the real $K$-th...
1994-07-05
2019-07-29
[ "dg-ga", "math.DG" ]
Jonathan Rosenberg and Stephan Stolz
dg-ga/9407001
Teichmuller Space is Not Gromov Hyperbolic
We prove that the Teichmuller Space of Riemann Surfaces of genus g>1, equipped with the Teichmuller metric, is not a Gromov Hyperbolic space.
1994-07-01
2008-02-03
[ "dg-ga", "math.DG" ]
Howard A. Masur and Michael Wolf
dg-ga/9406007
The Spectral Flow of the Odd Signature operator and Higher Massey Products
We show how to compute the spectral flow of the odd signature operator $\pm *d_{a_t}-d_{a_t}*$ along an analytic path of flat connections $a_t$ on a bundle over a closed odd-dimensional manifold in terms of Massey products in the DGLA of bundle-valued differential forms. To obtain this information, we set up a sequence...
1994-06-30
2008-02-03
[ "dg-ga", "math.DG" ]
Paul Kirk and Eric Klassen
dg-ga/9406005
$n$-transitivity of certain diffeomorphism groups
Some groups of real analytic diffeomorphism act n-transitively for each finite n.
1994-06-30
2008-02-03
[ "dg-ga", "math.DG" ]
Peter W. Michor, Cornelia Vizman
dg-ga/9406006
Basic differential forms for actions of Lie groups
A section of a Riemannian $G$-manifold $M$ is a closed submanifold $\Sigma$ which meets each orbit orthogonally. It is shown that the algebra of $G$-invariant differential forms on $M$ which are horizontal in the sense that they kill every vector which is tangent to some orbit, is isomorphic to the algebra of those dif...
1994-06-30
2008-02-03
[ "dg-ga", "math.DG" ]
Peter W. Michor
dg-ga/9406004
Moduli Spaces of Singular Yamabe Metrics
Complete, conformally flat metrics of constant positive scalar curvature on the complement of $k$ points in the $n$-sphere, $k \ge 2$, $n \ge 3$, were constructed by R\. Schoen [S2]. We consider the problem of determining the moduli space of all such metrics. All such metrics are asymptotically periodic, and we develop...
1994-06-30
2008-02-03
[ "dg-ga", "math.DG" ]
Rafe Mazzeo, Daniel Pollack and Karen Uhlenbeck
dg-ga/9406003
On the Existence of Jenkins-Strebel Differentials Using Harmonic Maps from Surfaces to Graphs
We give a new proof of the existence (\cite{HM}, \cite{Ren}) of a Jenkins-Strebel differential $\Phi$ on a Riemann surface $\SR$ with prescribed heights of cylinders by considering the harmonic map from $\SR$ to the leaf space of the vertical foliation of $\Phi$, thought of as a Riemannian graph. The novelty of the arg...
1994-06-29
2008-02-03
[ "dg-ga", "math.DG" ]
Michael Wolf
dg-ga/9406002
Characteristic Numbers and Generalized Path Integrals
This is an extended write-up of a talk given in April, 1993 in honor of Raoul Bott's 70th birthday. We first illustrate how some traditional topological and geometric invariants obey ``gluing laws'' inspired by those in classical and quantum field theory. Here we discuss characteristic numbers, particularly the Euler n...
1994-06-28
2008-02-03
[ "dg-ga", "math.DG" ]
Daniel S. Freed
dg-ga/9406001
On extremals with prescribed Lagrangian densities
Consider two manifolds~$M^m$ and $N^n$ and a first-order Lagrangian $L(u)$ for mappings $u:M\to N$, i.e., $L$ is an expression involving $u$ and its first derivatives whose value is an $m$-form (or more generally, an $m$-density) on~$M$. One is usually interested in describing the extrema of the functional $\Cal L(u) =...
1994-06-23
2008-02-03
[ "dg-ga", "math.DG" ]
Robert L. Bryant
funct-an/9412004
Diagonalization of compact operators in Hilbert modules over finite W*-algebras
It is known that a continuous family of compact operators can be diagonalized pointwise. One can consider this fact as a possibility of diagonalization of the compact operators in Hilbert modules over a commutative W*-algebra. The aim of the present paper is to generalize this fact for a finite W*-algebra $A$ not neces...
1994-12-16
2008-02-03
[ "funct-an", "math.OA" ]
V.M.Manuilov
funct-an/9412003
On dense subspaces in a class of Fr\'echet function spaces on R^n
When dealing with concrete problems in a function space on R^n, it is sometimes helpful to have a dense subspace consisting of functions of a particular type, adapted to the problem under consideration. We give a theorem that allows one to write down many of such subspaces in commonly occurring Fr\'echet function space...
1994-12-13
2008-02-03
[ "funct-an", "math.FA" ]
M.F.E. de Jeu (Mathematical Institute, Leiden University, The Netherlands)
funct-an/9412002
An Equivariant Brauer Group and Actions of Groups on C*-algebras
Suppose that $(G,T)$ is a second countable locally compact transformation group given by a homomorphism $\ell:G\to\Homeo(T)$, and that $A$ is a separable continuous-trace \cs-algebra with spectrum $T$. An action $\alpha:G\to\Aut(A)$ is said to cover $\ell$ if the induced action of $G$ on $T$ coincides with the original...
1994-12-12
2008-02-03
[ "funct-an", "math.OA" ]
David Crocker, Alex Kumjian, Iain Raeburn, and Dana Williams
funct-an/9412001
Berezin's quantization on flag manifolds and spherical modules
It is shown that the theory of spherical Harish-Chandra modules naturally provides the algebras of covariant, contravariant and mixed symbols on generalized flag manifolds. The general proof of the correspondence principle for all these symbol algebras is given.
1994-12-01
2015-04-21
[ "funct-an", "math.OA", "math.QA" ]
A.V.Karabegov
funct-an/9411008
Diagonalizing ''compact'' operators on Hilbert W*-modules
For W*-algebras A and self-dual Hilbert A-modules M we show that every self-adjoint, ''compact'' module operator on M is diagonalizable. Some specific properties of the eigenvalues and of the eigenvectors are described.
1994-11-24
2025-05-08
[ "funct-an", "math.OA" ]
Michael Frank and Vladimir M. Manuilov
funct-an/9411007
Characteristics of pairs of operators, Lie hybrids, Poisson brackets and nonlinear geometric algebra
Some algebraic, geometric and geometroalgebraic characteristics of pairs of operators are discussed.
1994-11-22
2008-02-03
[ "funct-an", "math.OA" ]
Denis Juriev
funct-an/9411006
Path spaces, continuous tensor products, and E_0 semigroups
We classify all continuous tensor product systems of Hilbert spaces which are ``infinitely divisible" in the sense that they have an associated logarithmic structure. These results are applied to the theory of E_0 semigroups to deduce that every E_0 semigroup which possesses sufficiently many ``decomposable" operators ...
1994-11-20
2008-02-03
[ "funct-an", "math.OA" ]
William Arveson
funct-an/9411005
Determinants of elliptic boundary problems for Dirac operators I. Local boundary conditions
We study functional determinants for Dirac operators on manifolds with boundary and discuss the ellipticity of boundary problems by using the Calder\'on projector. We give, for local boundary conditions, an explicit formula relating these determinants to the corresponding Green functions. We finally apply this result t...
1994-11-04
2016-08-14
[ "funct-an", "math.FA" ]
H. Falomir, R.E. Gamboa Sarav\'i, M.A. Muschietti, E.M. Santangelo and J.E.Solomin
funct-an/9411004
Time-Optimal Control Problem for the Swing and the Ski
This paper is concerned with a class of time-optimal control problems for the swing and the ski. We first consider the motion of a man standing on a swing. For simplicity, we neglect friction and air resistance and assume that the mass of the swinger is concentrated in his baricenter $B$. For the ski, we use the model ...
1994-11-03
2008-02-03
[ "funct-an", "math.FA" ]
Benedetto Piccoli
funct-an/9411002
Existence results for non-coercive variational problems
The aim of this paper is to give an existence result for a class of one-dimensional, non-convex, non-coercive problems in the Calculus of Variations. The main tools for the proof are an existence theorem in the convex case and the closure of the convex hull of the epigraph of functions strictly convex at infinity.
1994-11-03
2008-02-03
[ "funct-an", "math.FA" ]
Graziano Crasta and Annalisa Malusa
funct-an/9411003
An existence result for non-coercive non-convex problems
We consider a class of one--dimensional non--convex non--coercive problems in the Calculus of Variations. We prove an existence result for this class of problems using a Liapunov type theorem on the range of non--atomic measures.
1994-11-03
2008-02-03
[ "funct-an", "math.FA" ]
Graziano Crasta
funct-an/9411001
An Adiabatic Theorem for Singularly Perturbed Hamiltonians
The adiabatic approximation in quantum mechanics is considered in the case where the self-adjoint hamiltonian $H_0(t)$, satisfying the usual spectral gap assumption in this context, is perturbed by a term of the form $\epsilon H_1(t)$. Here $\epsilon \to 0$ is the adiabaticity parameter and $H_1(t)$ is a self-adjoint o...
1994-11-02
2008-02-03
[ "funct-an", "math.FA" ]
Alain Joye
funct-an/9410005
Landau Hamiltonians with Random Potentials: Localization and the Density of States
We prove the existence of localized states at the edges of the bands for the two-dimensional Landau Hamiltonian with a random potential, of arbitrary disorder, provided that the magnetic field is sufficiently large. The corresponding eigenfunctions decay exponentially with the magnetic field and distance. We also prove...
1994-10-18
2008-02-03
[ "funct-an", "math-ph", "math.FA", "math.MP" ]
J.M. Combes, P.D. Hislop
funct-an/9410004
Convolution and Limit Theorems for Conditionally Free Random Variables
We introduce the notion of a conditionally free product and conditionally free convolution. We describe this convolution both from a combinatorial point of view, by showing its connection with the lattice of non-crossing partitions, and from an analytic point of view, by presenting the basic formula for its $R$-transfo...
1994-10-17
2008-02-03
[ "funct-an", "math.OA" ]
Marek Bozejko, Michael Leinert, Roland Speicher
funct-an/9410003
Crossed products whose primitive ideal spaces are generalized trivial $\widehat G$-bundles
We characterize when the primitive ideal space of a crossed product $\acg$ of a \cs-algebra $A$ by a locally compact abelian group $G$ is a $\sigma$-trivial $\ghat G$-space for the dual $\ghat G$-action. Specifically, we show that $\Prim(\acg)$ is $\sigma$-trivial if and only if the quasi-orbit space is Hausdorff, the ...
1994-10-12
2016-08-31
[ "funct-an", "math.OA" ]
Siegfried Echterhoff and Dana Williams
funct-an/9410002
$L^p$-Spaces as Quasi *-Algebras
The Banach space $L^p(X,\mu)$, for $X$ a compact Hausdorff measure space, is considered as a special kind of quasi *-algebra (called CQ*-algebra) over the C*-algebra $C(X)$ of continuous functions on $X$. It is shown that, for $p \geq 2$, $(L^p(X,\mu), C(X))$ is *-semisimple (in a generalized sense). Some consequences ...
1994-10-05
2008-02-03
[ "funct-an", "math.OA" ]
F. Bagarello and C. Trapani
funct-an/9410001
Relative Convolutions. I. Properties and Applications
To study operator algebras with symmetries in a wide sense we introduce a notion of {\em relative convolution operators} induced by a Lie algebra. Relative convolutions recover many important classes of operators, which have been already studied (operators of multiplication, usual group convolutions, two-sided convolut...
1994-10-03
2008-02-03
[ "funct-an", "math.OA" ]
Vladimir V. Kisil
funct-an/9409004
The equivariant Brauer groups of commuting free and proper actions are isomorphic
If $X$ is a locally compact space which admits commuting free and proper actions of locally compact groups $G$ and $H$, then the Brauer groups $\Br_H(G/X)$ and $\Br_G(X/H)$ are naturally isomorphic.
1994-09-27
2008-02-03
[ "funct-an", "math.FA", "math.RT" ]
Alexander Kumjian, Iain Raeburn, and Dana P. Williams
funct-an/9409003
Classical and quantum dynamics of noncanonically coupled oscillators and Lie superalgebras
The classical and quantum dynamics of noncanonically coupled os- cillators is investigated in its relation to Lie superalgebras. It is shown that the quantum dynamics admits a hidden (super)hamiltonian formulation and, hence, preserves the initial operator relations.
1994-09-26
2008-02-03
[ "funct-an", "chao-dyn", "math.OA", "nlin.CD", "nlin.SI", "solv-int" ]
D.V.Juriev
funct-an/9409002
On an Application of Hypoellipticity to Solutions of Functional Equations
We study the regularity of solutions of functional equations of a generalized mean value type. In this paper we give sufficient conditions for the regularity by using hypoellipticity which is a concept of the theory of partial differential equations. Further we also give an affirmative answer to a conjecture of H.\'Swi...
1994-09-21
2016-08-31
[ "funct-an", "math.FA" ]
A. Tsutsumi and S. Haruki
funct-an/9409001
Approximate unitary equivalence of homomorphisms from O_{\infty}
We prove that if two homomorphisms from O_{\infty} to a purely infinite simple C*-algebra have the same class in KK-theory, and if either both are unital or both are nonunital, then they are approximately unitarily equivalent. It follows that O_{\infty} is classifiable in the sense of Rordam. In particular, Rordam's cl...
1994-09-07
2008-02-03
[ "funct-an", "math.OA" ]
Huaxin Lin and N. Christopher Phillips
funct-an/9408003
Interpolations between Bosonic and Fermionic Relations given by Generalized Brownian Motions (revised version)
We present an interpolation between the bosonic and fermionic relations. This interpolation is given by an object which we call `generalized Brownian motion' and which is characterized by a generalization of the pairing rule for the calculation of the moments of bosonic and fermionic fields. We develop some basic theor...
1994-08-31
2008-02-03
[ "funct-an", "math.OA" ]
Marek Bozejko and Roland Speicher
funct-an/9408004
Hilbert C*-modules over monotone complete C*-algebras
The aim of the present paper is to describe self-duality and C*- reflexivity of Hilbert {\bf A}-modules $\cal M$ over monotone complete C*-algebras {\bf A} by the completeness of the unit ball of $\cal M$ with respect to two types of convergence being defined, and by a structural criterion. The derived results generali...
1994-08-31
2025-04-29
[ "funct-an", "math.OA" ]
Michael Frank
funct-an/9408002
Completely Positive Maps on Coxeter Groups, Deformed Commutation Relations, and Operator Spaces
In this article we prove that quasi-multiplicative (with respect to the usual length function) mappings on the permutation group $\SSn$ (or, more generally, on arbitrary amenable Coxeter groups), determined by self-adjoint contractions fulfilling the braid or Yang-Baxter relations, are completely positive. We point out...
1994-08-30
2008-02-03
[ "funct-an", "math.OA" ]
Marek Bozejko and Roland Speicher
funct-an/9408001
Endomorphisms of B(H)
The unital endomorphisms of B(H) of (Powers) index n are classified by certain U(n)-orbits in the set of non-degenerate representations of the Cuntz algebra O_n on H. Using this, the corre- sponding conjugacy classes are identified, and a set of labels is given. This set is given as P modulo a certain non-smooth equiva...
1994-08-29
2008-02-03
[ "funct-an", "math.OA" ]
Ola Bratteli, Palle Jorgensen and Geoff Price
funct-an/9406005
An Algebraic Spin and Statistics Theorem
A spin-statistics theorem and a PCT theorem are obtained in the context of the superselection sectors in Quantum Field Theory on a 4-dimensional space-time. Our main assumption is the requirement that the modular groups of the von Neumann algebras of local observables associated with wedge regions act geometrically as ...
1994-06-23
2008-11-26
[ "funct-an", "hep-th", "math.OA" ]
Daniele Guido, Roberto Longo
funct-an/9406004
Douady's conjecture on Banach analytic spaces
We show that, as conjectured by Adrien Douady back in 1972, every complete metric space is homeomorphic (moreover, isometric) to the locus of zeros of an analytic map between two Banach spaces. As a corollary, a paracompact topological space admits the structure of a Banach analytic space if and only if it is metrizabl...
1994-06-20
2008-02-03
[ "funct-an", "math.FA" ]
Vladimir G. Pestov
funct-an/9406002
Lexicographic semigroupoids
The natural lexicographic semigroupoids associated with Cantor product spaces indexed by countable linear orders are classified. Applications are given to the classification of triangular operator algebras which are direct limits of upper triangular matrix algebras.
1994-06-07
2008-02-03
[ "funct-an", "math.OA" ]
S. C. Power
funct-an/9406003
On the Banach space isomorphism type of AF C*-algebras and their triangular subalgebras
It is shown that all the approximately finite dimensional C*-algebras which are not of Type I are isomorphic as Banach spaces. This generalises the matroid case given previously by Arazy. Analogous results are obtained for various families of triangular subalgebras of AF C*-algebras. In addition the classification of v...
1994-06-07
2008-02-03
[ "funct-an", "math.OA" ]
S. C. Power
funct-an/9406001
Infinite Lexicographic Products of Triangular Algebras
Some new connections are given between linear orderings and triangular operator algebras. A lexicograhic product is defined for triangular operator algebras and the Jacobson radical of an infinite lexicographic product of upper triangular matrix algebras is determined.
1994-06-07
2008-02-03
[ "funct-an", "math.OA" ]
S. C. Power
funct-an/9405005
Homology for operator algebras II : Stable homology for non-self-adjoint algebras
A new homology is defined for a non-self-adjoint operator algebra and distinguished masa which is based upon cycles and boundaries associated with complexes of partial isometries in the stable algebra. Under natural hypotheses the zeroth order group coincides with the $\ K_0$\ group of the generated C*-algebra. Several...
1994-05-18
2008-02-03
[ "funct-an", "math.OA" ]
S. C. Power
funct-an/9405004
Homology for operator algebras I: Spectral homology for reflexive algebras
A stable homology theory is defined for completely distributive CSL algebras in terms of the point-neighbourhood homology of the partially ordered set of meet-irreducible elements of the invariant projection lattice. This specialises to the simplicial homology of the underlying simplicial complex in the case of a digra...
1994-05-18
2008-02-03
[ "funct-an", "math.OA" ]
S. C. Power
funct-an/9405003
Epimorphisms of C*-algebras are surjective
We answer a question raised by V.G.Pestov in the affirmative.
1994-05-16
2008-02-03
[ "funct-an", "math.OA" ]
Karl H. Hofmann and Karl-H.Neeb
funct-an/9405002
No More Than Mechanics. I
One can introduce so-called {\em Plain Mechanics} having an {\bf operator realization}. Then the set of one-dimension representations of this operator realization may be identified with the Classical Mechanics. Different irreducible infinite-dimension representations may be recognized as Quantum Mechanics for different...
1994-05-02
2008-02-03
[ "funct-an", "math.OA" ]
Vladimir V. Kisil
funct-an/9405001
Twisted Partial Actions, A Classification of Stable C*-Algebraic Bundles (Preliminary Version)
We introduce the notion of continuous twisted partial actions of a locally compact group on a C*-algebra. With such, we construct an associated C*-algebraic bundle called the semidirect product bundle. Our main theorem shows that, given any C*-algebraic bundle which is second countable and whose unit fiber algebra is s...
1994-05-02
2008-02-03
[ "funct-an", "math.OA" ]
Ruy Exel