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gr-qc/9410007
Decoherence on Quantum Tunneling in the Multi-Dimensional Wave Function Approach
We consider fundamental problems on the understanding of the tunneling phenomena in the context of the multi-dimensional wave function. In this paper, we reconsider the quantum state after tunneling and extend our previous formalism to the case when the quantum state before tunneling is in a squeezed state. Through con...
1994-10-07
2010-11-01
[ "gr-qc" ]
Takahiro Tanaka
gr-qc/9410009
Short-distance Cut-off from the Quantum Dynamics of Fields in a Black Hole Spacetime
We stress the strongly observer-dependent nature of the fine-grained black hole entropy as computed by usual methods. From the point of view of a fiducial observer, the 1-loop renormalized energy-momentum tensor diverges at the horizon. Considering, more consistently, the computation of the black hole entropy in the ba...
1994-10-07
2009-09-25
[ "gr-qc", "astro-ph", "hep-th" ]
C.O. Lousto
gr-qc/9410006
Conservation Laws in the Quantum Mechanics of Closed Systems
We investigate conservation laws in the quantum mechanics of closed systems. We review an argument showing that exact decoherence implies the exact conservation of quantities that commute with the Hamiltonian including the total energy and total electric charge. However, we also show that decoherence severely limits th...
1994-10-06
2009-10-22
[ "gr-qc", "hep-th" ]
James B. Hartle, Raymond Laflamme, Donald Marolf
gr-qc/9410004
On the topology of stationary black holes
We prove that the domain of outer communication of a stationary, globally hyperbolic spacetime satisfying the null energy condition must be simply connected. Under suitable additional hypotheses, this implies, in particular, that each connected component of a cross-section of the event horizon of a stationary black hol...
1994-10-05
2010-04-06
[ "gr-qc" ]
P.T. Chrusciel, R.M. Wald
gr-qc/9410005
Bosonic physical states in N=1 supergravity?
It is argued that states in $N=1$ supergravity that solve all of the constraint equations cannot be bosonic in the sense of being independent of the fermionic degrees of freedom. (Based on a talk given by Miguel Ortiz at the 7th Marcel Grossmann Meeting.)
1994-10-05
2007-05-23
[ "gr-qc", "hep-th" ]
S. M. Carroll, D. Z. Freedman, M. E. Ortiz and D. N. Page
gr-qc/9410002
Can Galactic Observations Be Explained by a Relativistic Gravity Theory?
We consider the possibility of an alternative gravity theory explaining the dynamics of galactic systems without dark matter. From very general assumptions about the structure of a relativistic gravity theory we derive a general expression for the metric to order $(v/c)^2$. This allows us to compare the predictions of ...
1994-10-04
2009-10-22
[ "gr-qc" ]
Vadim V. Zhytnikov and James M. Nester
gr-qc/9410003
Initial Data for General Relativity with Toroidal Conformal Symmetry
A new class of time-symmetric solutions to the initial value constraints of vacuum General Relativity is introduced. These data are globally regular, asymptotically flat (with possibly several asymptotic ends) and in general have no isometries, but a $U(1)\times U(1)$ group of conformal isometries. After decomposing th...
1994-10-04
2009-12-30
[ "gr-qc" ]
Robert Beig and Sascha Husa
gr-qc/9410001
Fermi-Walker coordinates in 2+1 dimensional gravity
It is shown that in 2+1 dimensions the Fermi-Walker gauge allows the general solution of the problem of determining the metric from the sources in terms of simple quadratures. This technique is used to solve the problem of the occurrence of closed time like curves (CTC's) in stationary solutions. In fact the Fermi-Walk...
1994-10-03
2007-05-23
[ "gr-qc", "hep-th" ]
P. Menotti and D. Seminara
gr-qc/9409062
The Final Fate of Spherical Inhomogeneous Dust Collapse
We examine the role of the initial density and velocity distribution in the gravitational collapse of a spherical inhomogeneous dust cloud. Such a collapse is described by the Tolman-Bondi metric which has two free functions: the `mass-function' and the `energy function', which are determined by the initial density and...
1994-09-30
2009-10-22
[ "gr-qc", "astro-ph", "hep-th" ]
T. P. Singh and P. S. Joshi
gr-qc/9409059
On a possible solution for the Polonyi problem in string cosmology
We establish the main features of homogeneous and isotropic dilaton, metric and Yang-Mills configurations in a cosmological framework. We identify a new energy exchange term between the dilaton and the Yang-Mills field which may lead to a possible solution to the Polonyi problem in 4-dimensional string models.
1994-09-29
2007-05-23
[ "gr-qc" ]
M. C. Bento and O. Bertolami
gr-qc/9409060
Modification of the Coulomb potential from a Kaluza-Klein model with a Gauss-Bonnet term in the action
In four dimensions a Gauss-Bonnet term in the action corre- sponds to a total derivative, and it does not contribute to the classical equations of motion. For higher-dimensional geometries this term has the interesting property (shared with other dimensionally continued Euler densities) that when the action is varied w...
1994-09-29
2010-11-01
[ "gr-qc", "hep-th" ]
H. H. Soleng and O. Gron
gr-qc/9409061
What is the reference frame of an accelerated observer?
The general construction of extended refrence frames for noninertial observers in flat space is studied. It is shown that, if the observer moves inertially before and after an arbitrary acceleration and rotation, the region where reference frames can coincide with an inertial system is bounded for final velocities exce...
1994-09-29
2009-10-22
[ "gr-qc" ]
K.-P. Marzlin
gr-qc/9409058
A Quantum-Driven Time (QDT) Quantization of the Taub Cosmology
We present here an application of a new quantization scheme. We quantize the Taub cosmology by quantizing only the anisotropy parameter $\beta$ and imposing the super-Hamiltonian constraint as an expectation-value equation to recover the relationship between the scale factor $\Omega$ and the time $t$. This approach app...
1994-09-28
2007-05-23
[ "gr-qc" ]
Arkady Kheyfets and Warner A. Miller
gr-qc/9409055
Effects of weak self-interactions in a relativistic plasma on cosmological perturbations
The exact solutions for linear cosmological perturbations which have been obtained for collisionless relativistic matter within thermal field theory are extended to a self-interacting case. The two-loop contributions of scalar $\lambda\phi^4$ theory to the thermal graviton self-energy are evaluated, which give the $O(\...
1994-09-27
2009-12-30
[ "gr-qc", "astro-ph", "hep-ph" ]
H. Nachbagauer, A. K. Rebhan, D. J. Schwarz
gr-qc/9409054
Gravitational Waves from a Particle Orbiting Around a Rotating Black Holes: Post-Newtonian Expansion
Using the Teukolsky and Sasaki-Nakamura equations for the gravitational perturbation of the Kerr spacetime, we calculate the post-Newtonian expansion of the energy and angular momentum luminosities of gravitational waves from a test particle orbiting around a rotating black hole up through ${\rm P^{5/2}N}$ order beyond...
1994-09-27
2009-10-09
[ "gr-qc", "astro-ph" ]
Masaru Shibata, Misao Sasaki, Hideyuki Tagoshi and Takahiro Tanaka
gr-qc/9409056
Conditions for inflation in an initially inhomogeneous universe
Using a long wavelength iteration scheme to solve Einstein's equations near the Big-Bang singularity of a universe driven by a massive scalar field, we find how big initial quasi-isotropic inhomogeneities can be before they can prevent inflation to set in.
1994-09-27
2009-10-22
[ "gr-qc", "astro-ph" ]
Nathalie Deruelle and Dalia S. Goldwirth
gr-qc/9409053
Nonequilibrium Quantum Fields in Cosmology: Comments on Selected Current Topics
Concepts of quantum open systems and ideas of correlation dynamics in nonequilibrium statistical mechanics, as well as methods of closed-time-path effective action and influence functional in quantum field theory can be usefully applied for the analysis of quantum statistical processes in gravitation and cosmology. We ...
1994-09-27
2007-05-23
[ "gr-qc", "hep-th" ]
B. L. Hu (Department of Physics, University of Maryland, College Park, MD and Institute for Advanced Study, Princeton, New Jersey, USA)
gr-qc/9409057
Gravitational Radiation from Nonaxisymmetric Instability in a Rotating Star
We present the first calculations of the gravitational radiation produced by nonaxisymmetric dynamical instability in a rapidly rotating compact star. The star deforms into a bar shape, shedding $\sim 4\%$ of its mass and $\sim 17\%$ of its angular momentum. The gravitational radiation is calculated in the quadrupole a...
1994-09-27
2009-01-23
[ "gr-qc", "astro-ph" ]
J. L. Houser, J. M. Centrella, and S. C. Smith
gr-qc/9409052
The Statistical Mechanics of the (2+1)-Dimensional Black Hole
The presence of a horizon breaks the gauge invariance of (2+1)-dimensional general relativity, leading to the appearance of new physical states at the horizon. I show that the entropy of the (2+1)-dimensional black hole can be obtained as the logarithm of the number of these microscopic states.
1994-09-26
2010-04-28
[ "gr-qc", "hep-th" ]
S. Carlip
gr-qc/9409050
Higgs Mechanism and the Structure of the Energy-Momentum Tensor in Einstein Gravity and Conformal Gravity
In the standard treatment of the Einstein gravitational theory the energy-momentum tensor has always been taken to be composed of perfect fluid aggregates of kinematic Newtonian point test particles with fundamental mechanical masses. Moreover, this standard prescription was not revised after the discovery of the mass-...
1994-09-23
2007-05-23
[ "gr-qc" ]
Philip D. Mannheim (University of Connecticut) and Demosthenes Kazanas (NASA/Goddard Space Flight Center)
gr-qc/9409049
Observables and a Hilbert Space for Bianchi IX
We consider a quantization of the Bianchi IX cosmological model based on taking the constraint to be a self-adjoint operator in an auxiliary Hilbert space. Using a WKB-style self-consistent approximation, the constraint chosen is shown to have only continuous spectrum at zero. Nevertheless, the auxiliary space induces ...
1994-09-23
2010-04-06
[ "gr-qc" ]
Donald Marolf
gr-qc/9409051
A Three-Dimensional Hydrodynamics Code for Modeling Sources of Gravitational Radiation
We have developed a 3-D Eulerian hydrodynamics code to model sources of gravitational radiation. The code is written in cylindrical coordinates $(\varpi,z,\varphi)$ and has moving grids in the $\varpi$ and $z$-directions. We use Newtonian gravity and calculate the gravitational radiation in the quadrupole approximation...
1994-09-23
2009-10-22
[ "gr-qc", "astro-ph" ]
Scott C. Smith, Joan M. Centrella, and Sean P. Clancy
gr-qc/9409048
Infinite Blueshift of Charged Null Particles
We demonstrate that charged null particles can be infinitely blue\-shifted in a Kerr-Newman spacetime. The surface of infinite blueshift can be outside of the ergosphere in a Kerr-Newman spacetime, and outside of the outer event horizon for a Reissner-Nordstrom spacetime. Implications for extensions of the standard mod...
1994-09-22
2008-02-03
[ "gr-qc", "hep-ph" ]
R.B. Mann and W.N. Sajko
gr-qc/9409046
The General Self-dual solution of the Einstein Equations
We obtain the most general explicit (anti)self-dual solution of the Einstein equations. We find that any (anti)self-dual solution can be characterised by three free functions of which one is harmonic. Any stationary (anti)self-dual solution can be characterised by a harmonic function. It turns out that the form of the ...
1994-09-21
2007-05-23
[ "gr-qc" ]
Sucheta Koshti and Naresh Dadhich
gr-qc/9409045
An Analytic Model with Critical Behavior in Black Hole Formation
A simple analytic model is presented which exhibits a critical behavior in black hole formation, namely, collapse of a thin shell coupled with outgoing null fluid. It is seen that the critical behavior is caused by the gravitational nonlinearity near the event horizon. We calculate the value of the critical exponent an...
1994-09-21
2009-10-22
[ "gr-qc", "hep-th" ]
Tatsuhiko Koike and Takashi Mishima
gr-qc/9409047
Embedding initial data for black hole collisions
We discuss isometric embedding diagrams for the visualization of initial data for the problem of the head-on collision of two black holes. The problem of constructing the embedding diagrams is explicitly presented for the best studied initial data, the Misner geometry. We present a partial solution of the embedding dia...
1994-09-21
2010-04-06
[ "gr-qc" ]
Joseph D. Romano and Richard H. Price
gr-qc/9409043
Scale anomalies imply violation of the averaged null energy condition
Considerable interest has recently been expressed regarding the issue of whether or not quantum field theory on a fixed but curved background spacetime satisfies the averaged null energy condition (ANEC). A comment by Wald and Yurtsever [Phys. Rev. D43, 403 (1991)] indicates that in general the answer is no. In this no...
1994-09-20
2009-10-22
[ "gr-qc", "hep-th" ]
Matt Visser
gr-qc/9409041
Cosmological solutions of the Vlasov-Einstein system with spherical, plane, and hyperbolic symmetry
The Vlasov-Einstein system describes a self-gravitating, collisionless gas within the framework of general relativity. We investigate the initial value problem in a cosmological setting with spherical, plane, or hyperbolic symmetry and prove that for small initial data solutions exist up to a spacetime singularity whic...
1994-09-20
2015-06-25
[ "gr-qc" ]
Gerhard Rein
gr-qc/9409044
Is there a connection between no-hair behavior and universality in gravitational collapse?
We apply linear perturbation theory to the study of the universality and criticality first observed by Choptuik in gravitational collapse. Since these are essentially nonlinear phenomena our attempt is only a rough approximation. In spite of this, universal behavior of the final black hole mass is observed with an expo...
1994-09-20
2009-10-22
[ "gr-qc" ]
Jorge Pullin
gr-qc/9409042
Decoherence of Homogeneous and Isotropic Metrics in the Presence of Massive Vector Fields
Retrieval of classical behaviour in quantum cosmology is usually discussed in the framework of minisuperspace models in the presence of scalar fields together with the inhomogeneous modes either of the gravitational or of the scalar fields. In this work we propose alternatively a model where the scalar field is replace...
1994-09-20
2007-05-23
[ "gr-qc" ]
O. Bertolami and P.V. Moniz
gr-qc/9409039
Spherically Symmetric Solutions in M\o ller's Tetrad Theory of Gravitation
The general solution of M\o ller's field equations in case of spherical symmetry is derived. The previously obtained solutions are verified as special cases of the general solution.
1994-09-19
2008-11-26
[ "gr-qc" ]
F. I. Mikhail, M. I. Wanas, E. I. Lashin, and Ahmed Hindawi
gr-qc/9409040
A remark on kinks and time machines
We describe an elementary proof that a manifold with the topology of the Politzer time machine does not admit a nonsingular, asymptotically flat Lorentz metric.
1994-09-19
2009-10-22
[ "gr-qc" ]
Ulvi Yurtsever
gr-qc/9409038
The Gravitational and Electrostatic Fields Far from an Isolated Einstein-Maxwell Source
The exterior solution for an arbitrary charged, massive source, is studied as a static deviation from the Reissner-Nordstr\o m metric. This is reduced to two coupled ordinary differential equations for the gravitational and electrostatic potential functions. The homogeneous equations are explicitly solved in the partic...
1994-09-18
2009-10-22
[ "gr-qc" ]
J. Ocariz, H. Rago
gr-qc/9409037
Properties of Consistent Histories
We describe some properties of consistent sets of histories in the Gell-Mann--Hartle formalism, and give an example to illustrate that one cannot recover the standard predictions, retrodictions and inferences of quasiclassical physics using the criterion of consistency alone.
1994-09-17
2018-07-17
[ "gr-qc", "hep-th", "quant-ph" ]
Fay Dowker, Adrian Kent
gr-qc/9409036
The Spectral Analysis Inner Product for Quantum Gravity
This submission to the Proceedings of the Seventh Marcel-Grossman Conference is an advertisement for the use of the ``spectral analysis inner product" for minisuperspace models in quantum gravity.
1994-09-16
2007-05-23
[ "gr-qc" ]
Donald Marolf
gr-qc/9409034
Inside a Spinning Black String
We show that mass inflation occurs inside spinning black cosmic string, which is a solution of a low-energy effective string theory in $(3+1)$-dimensions. This confirms Poisson and Israel's conjecture that the inner mass parameter diverges even if spacetime is not spherically symmetric.
1994-09-16
2009-10-22
[ "gr-qc", "hep-th" ]
J.S.F. Chan and R.B. Mann
gr-qc/9409035
Self-Similar Scalar Field Collapse: Naked Singularities and Critical Behaviour
Homothetic scalar field collapse is considered in this article. By making a suitable choice of variables the equations are reduced to an autonomous system. Then using a combination of numerical and analytic techniques it is shown that there are two classes of solutions. The first consists of solutions with a non-singul...
1994-09-16
2009-10-22
[ "gr-qc" ]
Patrick R Brady
gr-qc/9409033
Massive Superstrings are Black Holes
We argue that it is inconsistent to ignore the gravitational backreaction for on-shell superstring states at the Planck mass and beyond, and that these quantum states become Kerr black holes in the classical limit. Consequences are discussed.
1994-09-15
2009-10-22
[ "gr-qc", "astro-ph", "hep-ph", "hep-th" ]
Paul H. Frampton and Thomas W. Kephart
gr-qc/9409032
Extrinsic Time in Quantum Cosmology
An extrinsic time is identified in most isotropic and homogeneous cosmological models by matching them with the ideal clock - a parametrized system whose only "degree of freedom" is time -. Once this matching is established, the cosmological models are quantized in the same way as the ideal clock. The space of solution...
1994-09-14
2009-10-22
[ "gr-qc" ]
S.C.Beluardi and Rafael Ferraro
gr-qc/9409028
On maximum number of decoherent histories
It is shown that $N^2$ is the upper limit for the number of histories in a decohering family of $N$-state quantum system. Simple criterion is found for a family of $N^2$ fine grained decohering histories of Gell-Mann and Hartle to be identical with a family of Griffiths' consistent quantum trajectories.
1994-09-14
2008-02-03
[ "gr-qc" ]
Lajos Diosi
gr-qc/9409029
A Method for Calculating the Structure of (Singular) Spacetimes in the Large
A formalism and its numerical implementation is presented which allows to calculate quantities determining the spacetime structure in the large directly. This is achieved by conformal techniques by which future null infinity ($\Scri{}^+$) and future timelike infinity ($i^+$) are mapped to grid points on the numerical g...
1994-09-14
2010-11-01
[ "gr-qc" ]
Peter Huebner
gr-qc/9409030
Black holes cannot support conformal scalar hair
It is shown that the only static asymptotically flat non-extrema black hole solution of the Einstein-conformally invariant scalar field equations having the scalar field bounded on the horizon, is the Schwarzschild one. Thus black holes cannot be endowed with conformal scalar hair of finite length.
1994-09-14
2014-11-17
[ "gr-qc" ]
T. Zannias
gr-qc/9409031
Bibliography of Publications related to Classical and Quantum Gravity in terms of the Ashtekar Variables
This bibliography attempts to give a comprehensive overview of all the literature related to the Ashtekar variables. The original version was compiled by Peter H\"ubner in 1989, and it has been subsequently updated by Gabriela Gonzalez, Bernd Br\"ugmann, and Troy Schilling. Information about additional literature, new ...
1994-09-14
2007-05-23
[ "gr-qc" ]
Troy A. Schilling
gr-qc/9409024
The Role of the Apparent Horizon in the Evolution of Robinson-Trautman %%EINSTEIN-Maxwell Spacetimes
The `runaway solutions' of the Lorentz-Dirac equation of a charged particle interacting with its own field in classical electrodynamics are well-known. This type of self accelerated phenomena also exists in the solutions of the Einstein-Maxwell equations in general relativity. In particular, runaway solutions occur in ...
1994-09-13
2007-05-23
[ "gr-qc" ]
Anthony W.C.Lun and Ernest W.M.Chow
gr-qc/9409025
The Bianchi Ix (MIXMASTER) Cosmological Model is Not Integrable
The perturbation of an exact solution exhibits a movable transcendental essential singularity, thus proving the nonintegrability. Then, all possible exact particular solutions which may be written in closed form are isolated with the perturbative Painlev\'e test; this proves the inexistence of any vacuum solution other...
1994-09-13
2007-05-23
[ "gr-qc" ]
A.~Latifi (Universit\'e libre de Bruxelles), M.~Musette (Vrije Universiteit Brussel) and R.~Conte (CEA, Centre d'\'etudes de Saclay)
gr-qc/9409022
Spinors and the reference point of quasilocal energy
This paper investigates the relationship between the quasilocal energy of Brown and York and certain spinorial expressions for gravitational energy constructed from the Witten-Nester integral. A key feature of the Brown-York method for defining quasilocal energy is that it allows for the freedom to assign the reference...
1994-09-13
2010-04-06
[ "gr-qc" ]
Stephen R. Lau
gr-qc/9409026
Quantum Fluctuations of Planck Mass as Mutation Mechanism in a Theory of Evolution of the Universe
Contributed talk at the Seventh Marcel Grossman Meeting on Gravity, June 24-30. A theory of evolution of the universe requires both a mutation mechanism and a selection mechanism. We believe that both can be encountered in the stochastic approach to quantum cosmology. In Brans-Dicke chaotic inflation, the quantum fluct...
1994-09-13
2007-05-23
[ "gr-qc", "astro-ph" ]
Juan Garcia-Bellido
gr-qc/9409027
Gravitational Analog of the Aharonov-Casher Effect
The gravitational interaction between a massive particle and a spinning particle in the weak-field limit is studied. We show that a system of a spinning point-like particle and a massive rod exhibit a topological effect analogous to the electromagnetic Aharonov-Casher effect. We discuss the effect also for systems with...
1994-09-13
2009-10-22
[ "gr-qc" ]
Benni Reznik
gr-qc/9409023
Evaporating Black Holes And An Entropic Scale-Hierarchy
It is argued that a characteristic length may be associated with the entropic state of a spherically symmetric black hole in the cosmological context. This length is much smaller than the Schwarzschild-radius of a black hole and may act as a regulator of arbitrarily high frequencies apparently entering the usual deriva...
1994-09-12
2007-05-23
[ "gr-qc" ]
Hadi Salehi
gr-qc/9409021
What Cavities?
Most spherical thin shells, enclosing black body radiation satisfy the dominant energy condition if they have at least $\simeq 30\%$ of the total mass-energy. Containers with less mass energy, able to sustain high pressures, contain mostly unstable radiation. If they have negligible mass energy they are unable to susta...
1994-09-12
2010-04-06
[ "gr-qc" ]
Joseph Katz and Yasunari Okuta
gr-qc/9409020
Exact Einstein-scalar field solutions for formation of black holes in a cosmological setting
We consider self-interacting scalar fields coupled to gravity. Two classes of exact solutions to Einstein's equations are obtained: the first class corresponds to the minimal coupling, the second one to the conformal coupling. One of the solutions is shown to describe a formation of a black hole in a cosmological setti...
1994-09-11
2010-04-06
[ "gr-qc", "astro-ph", "hep-th" ]
Oleg A. Fonarev
gr-qc/9409018
How Objective is Black Hole Entropy?
The objectivity of black hole entropy is discussed in the particular case of a Schwarzchild black hole. Using Jaynes' maximum entropy formalism and Euclidean path integral evaluation of partition function, it is argued that in the semiclassical limit when the fluctutation of metric is neglected, the black hole entropy ...
1994-09-10
2007-05-23
[ "gr-qc" ]
Y.K.Lau
gr-qc/9409019
Anomaly In 2d-Gravity Coupled To Matter Fields
In 1+1 dimensions, the Wheeler-DeWitt equation cannot be imposed owing to an anomaly in its commutator with the diffeomorphism constraint. A similar obstruction prevents also a semiclassical definition of a WKB local time. (Talk given at the 7th Marcel Grossman Meeting on General Relativity, Stanford, July 28, 1994.)
1994-09-10
2008-02-03
[ "gr-qc" ]
Daniel Cangemi
gr-qc/9409016
Comments on the multi-dimensional Wheeler-DeWitt equation
It is argued heuristically -- using an ${\bf S}^3 \times {\bf S}^6$ minisuperspace model -- that there might be a fundamental quantum gravity effect stabilizing internal spaces with non-vanishing Ricci curvature.
1994-09-09
2009-09-25
[ "gr-qc" ]
Franz Embacher
gr-qc/9409017
Critique of weakly decohering and linearly positive histories
The usual composition rule of independent systems, as applied to decoherent histories or to linearly positive histories, requires (at least) medium decoherence and, consequently, a second constraint for the linearly positive histories of Goldstein and Page. Other plausible classical features, valid for medium decoheren...
1994-09-09
2007-05-23
[ "gr-qc" ]
Lajos Diosi
gr-qc/9409013
Entropy, Area, and Black Hole Pairs
We clarify the relation between gravitational entropy and the area of horizons. We first show that the entropy of an extreme Reissner-Nordstr\"om black hole is $zero$, despite the fact that its horizon has nonzero area. Next, we consider the pair creation of extremal and nonextremal black holes. It is shown that the ac...
1994-09-08
2008-11-26
[ "gr-qc", "hep-th" ]
S. W. Hawking, Gary T. Horowitz, and Simon F. Ross
gr-qc/9409014
Consistency of Semiclassical Gravity
We discuss some subtleties which arise in the semiclassical approximation to quantum gravity. We show that integrability conditions prevent the existence of Tomonaga-Schwinger time functions on the space of three-metrics but admit them on superspace. The concept of semiclassical time is carefully examined. We point out...
1994-09-08
2010-04-06
[ "gr-qc" ]
D. Giulini and C. Kiefer
gr-qc/9409015
Do We Understand Black Hole Entropy ?
I review various proposals for the nature of black hole entropy and for the mechanism behind the operation of the generalized second law. I stress the merits of entanglement entropy {\tenit qua\/} black hole entropy, and point out that, from an operational viewpoint, entanglement entropy is perfectly finite. Problems w...
1994-09-08
2009-09-25
[ "gr-qc", "astro-ph", "hep-th" ]
Jacob D. Bekenstein
gr-qc/9409012
The No-Boundary Wave Function and the Duration of the Inflationary Period
For the simplest minisuperspace model based on a homogeneous, isotropic metric and a minimally coupled scalar field we derive analytic expressions for the caustic which separates Euklidean and Minkowskian region and its breakdown value $\p_*$. This value represents the prediction of the no-boundary wave function for th...
1994-09-07
2008-11-26
[ "gr-qc" ]
A. Lukas
gr-qc/9409008
Dumb Holes and the Effects of High Frequencies on Black Hole Evaporation
The naive calculation of black hole evaporation makes the thermal emission depend on the arbitrary high frequency behaviour of the theory where the theory is certainly wrong. Using the sonic analog to black holes-- dumb holes-- I show numerically that a change in the dispersion relation at high frequencies does not see...
1994-09-06
2009-10-22
[ "gr-qc" ]
W. G. Unruh (Univ. of BC)
gr-qc/9409011
Lifetimes of spherically symmetric closed universes
It is proven that any spherically symmetric spacetime that possesses a compact Cauchy surface $\Sigma$ and that satisfies the dominant-energy and non-negative-pressures conditions must have a finite lifetime in the sense that all timelike curves in such a spacetime must have a length no greater than $10 \max_\Sigma(2m)...
1994-09-06
2010-11-01
[ "gr-qc" ]
Gregory A. Burnett
gr-qc/9409009
Global Properties of Locally Spatially Homogeneous Cosmological Models with Matter
The existence and nature of singularities in locally spatially homogeneous solutions of the Einstein equations coupled to various phenomenological matter models is investigated. It is shown that, under certain reasonable assumptions on the matter, there are no singularities in an expanding phase of the evolution and th...
1994-09-06
2015-06-25
[ "gr-qc" ]
Alan D. Rendall
gr-qc/9409007
Essay on mesoscopic and quantum brain
In the pure essay style (no mathematical formulas), I present a number of speculative reflections and suggestions on possible applications of mesoscopic methods and of quantum mechanical concepts to as such a complex system as the human brain. As an initial guide for this essay I used ``The Emperor's New Mind" of Roger...
1994-09-05
2008-02-03
[ "gr-qc" ]
H.C. Rosu
gr-qc/9409006
Topology Changes by Quantum Tunneling in Four Dimensions
We investigate topology-changing processes in 4-dimensional quantum gravity with a negative cosmological constant. By playing the ``gluing-polytope game" in hyperbolic geometry, we explicitly construct an instanton-like solution without singularity. Because of cusps, this solution is non-compact but has a finite volume...
1994-09-05
2019-08-15
[ "gr-qc", "hep-th" ]
Ding Shuxue, Yasushige Maeda and Masaru Siino
gr-qc/9409010
Indeterministic Quantum Gravity
A theory which claims to describe all the universe is advanced. It unifies general relativity, quantum field theory, and indeterministic conception. Basic entities are: classical metric tensor $g$, cosmic reference frame (including cosmic time $t$), operator $T$ of energy-momentum tensor, Hamiltonian $H_t$, and state v...
1994-09-05
2007-05-23
[ "gr-qc" ]
Vladimir S. Mashkevich
gr-qc/9409004
MATTERS OF GRAVITY, a newsletter for the gravity community, Number 4
Table of contents Editorial. Gravity News: Report on the APS topical group in gravitation, Beverly Berger. Research briefs: Gravitational microlensing and the search for dark matter, Bohdan Paczynski. Laboratory gravity: the G mystery, Riley Newman. LIGO project update, Stan Whitcomb. Conference Reports...
1994-09-02
2007-05-23
[ "gr-qc" ]
Jorge Pullin (Editor)
gr-qc/9409005
Spacetime Information
In usual quantum theory, the information available about a quantum system is defined in terms of the density matrix describing it on a spacelike surface. This definition must be generalized for extensions of quantum theory which do not have a notion of state on a spacelike surface. It must be generalized for the genera...
1994-09-02
2009-10-22
[ "gr-qc", "hep-th" ]
James B. Hartle
gr-qc/9409003
Nonlinearity in Quantum Theory and Closed Timelike Curves
We examine consequences of the density matrix approach to quantum theory in the context of a model spacetime containing closed timelike curves and find that in general, an initially pure state will evolve in a nonlinear way to a mixed quantum state. CPT invariance and the implications of this nonlinearity for the stati...
1994-09-02
2009-10-22
[ "gr-qc", "hep-th" ]
M.J.Cassidy
gr-qc/9409001
Dust as a Standard of Space and Time in Canonical Quantum Gravity
The coupling of the metric to an incoherent dust introduces into spacetime a privileged dynamical reference frame and time foliation. The comoving coordinates of the dust particles and the proper time along the dust worldlines become canonical coordinates in the phase space of the system. The Hamiltonian constraint can...
1994-09-01
2009-07-09
[ "gr-qc" ]
J.D. Brown and K.V. Kuchar
gr-qc/9409002
Qualitative Analysis of Brans-Dicke Universes with a Cosmological Constant
Solutions to flat space Friedmann-Robertson-Walker cosmologies in Brans-Dicke theory with a cosmological constant are investigated. The matter is modelled as a $\gamma$-law perfect fluid. The field equations are reduced from fourth order to second order through a change of variables, and the resulting two-dimensional s...
1994-09-01
2009-10-22
[ "gr-qc" ]
Shawn J. Kolitch
gr-qc/9408044
A Schrodinger Equation for Quantum Universes
We discuss how to fix the gauge in the canonical treatment of Lagrangians, with finite number of degrees of freedom, endowed with time reparametrization invariance. The motion can then be described by an effective Hamiltonian acting on the gauge shell canonical space. The system is then suited for quantization. We appl...
1994-09-01
2009-10-22
[ "gr-qc" ]
Marco Cavaglia, Vittorio de Alfaro and Alexandre T. Filippov
gr-qc/9408038
Characterisation of orthogonal perfect fluid cosmological spacetimes
We consider the general orthogonal metric separable in space and time variables in comoving coordinates. We then characterise perfect fluid models admitted by such a metric. It turns out that the homogeneous models can only be either FLRW or Bianchi I while the inhomogeneous ones can only admit $G_2 $ (two mutually as ...
1994-08-31
2007-05-23
[ "gr-qc" ]
Naresh Dadhich, L.K. Patel, K.S. Govinder and P.G.L. Leach
gr-qc/9408043
Quasi-Normal Mode Expansion for Linearized Waves in Gravitational Systems
The quasinormal modes (QNM's) of gravitational systems modeled by the Klein-Gordon equation with effective potentials are studied in analogy to the QNM's of optical cavities. Conditions are given for the QNM's to form a complete set, i.e., for the Green's function to be expressible as a sum over QNM's, answering a conj...
1994-08-31
2016-08-31
[ "gr-qc" ]
E.S.C. Ching, P.T. Leung, W.M. Suen and K. Young
gr-qc/9408041
The Head-On Collision of Two Equal Mass Black Holes Peter Anninos
We study the head-on collision of two equal mass, nonrotating black holes. Various initial configurations are investigated, including holes which are initially surrounded by a common apparent horizon to holes that are separated by about $20M$, where $M$ is the mass of a single black hole. We have extracted both $\ell =...
1994-08-31
2009-10-22
[ "gr-qc" ]
David Hobill, Edward Seidel, Larry Smarr and Wai-Mo Suen
gr-qc/9408042
The Head-On Collision of Two Equal Mass Black Holes: Numerical Methods
The head-on collision of two nonrotating axisymmetric equal mass black holes is treated numerically. We take as initial data the single parameter family of time-symmetric solutions discovered by Misner which consists of two Einstein-Rosen bridges that can be placed arbitrarily distant from one another. A number of prob...
1994-08-31
2016-08-31
[ "gr-qc" ]
Peter Anninos, David Hobill, Edward Seidel, Larry Smarr and Wai-Mo Suen
gr-qc/9408037
Response of finite-time particle detectors in non-inertial frames and curved spacetime
The response of the Unruh-DeWitt type monopole detectors which were coupled to the quantum field only for a finite proper time interval is studied for inertial and accelerated trajectories, in the Minkowski vacuum in (3+1) dimensions. Such a detector will respond even while on an inertial trajctory due to the transient...
1994-08-31
2009-10-22
[ "gr-qc" ]
L.Sriramkumar and T.Padmanabhan
gr-qc/9408039
On the remote sensing of Hawking grey pulses
This is a short note on the black hole remote-sensing problem, i.e., finding out `surface' temperature distributions of various types of small (micron-sized) black holes from the spectral measurements of their Hawking grey pulses. Chen's modified Moebius inverse transform is illustrated in this context
1994-08-31
2009-10-22
[ "gr-qc", "astro-ph" ]
H.C. Rosu
gr-qc/9408040
General form of thermodynamical entropy for black hole
The entropy of a black hole can be different from a quarter of the area even at the semiclassical level.
1994-08-31
2010-11-01
[ "gr-qc", "hep-th" ]
A. Ghosh and P. Mitra
gr-qc/9408036
Calculation of gravitational wave forms from black hole collisions and disk collapse: Applying perturbation theory to numerical spacetimes
Many simulations of gravitational collapse to black holes become inaccurate before the total emitted gravitational radiation can be determined. The main difficulty is that a significant component of the radiation is still in the near-zone, strong field region at the time the simulation breaks down. We show how to calcu...
1994-08-30
2009-10-22
[ "gr-qc" ]
Andrew M. Abrahams, Stuart L. Shapiro, and Saul A. Teukolsky
gr-qc/9408035
Exact solutions of Einstein and Einstein-scalar equations in 2 + 1 dimensions
A nonstatic and circularly symmetric exact solution of the Einstein equations (with a cosmological constant $\Lambda$ and null fluid) in $2+1$ dimensions is given. This is a nonstatic generalization of the uncharged spinless BTZ metric. For $\Lambda = 0 $, the spacetime is though not flat, the Kretschmann invariant van...
1994-08-29
2009-10-22
[ "gr-qc", "hep-th" ]
K. S. Virbhadra
gr-qc/9408034
A Comment on Junction and Energy Conditions in Thin Shells
This comment contains a suggestion for a slight modification of Israel's covariant formulation of junction conditions between two spacetimes, placing both sides on equal footing with normals having uniquely defined orientations. The signs of mass energy densities in thin shells at the junction depend not only on the or...
1994-08-26
2010-04-06
[ "gr-qc" ]
D. S. Goldwirth and J. Katz
gr-qc/9408033
Chern-Simons functional and the no-boundary proposal in Bianchi IX quantum cosmology
The Chern-Simons functional $S_{\rm CS}$ is an exact solution to the Ashtekar-Hamilton-Jacobi equation of general relativity with a nonzero cosmological constant. In this paper we consider $S_{\rm CS}$ in Bianchi type IX cosmology with $S^3$ spatial surfaces. We show that among the classical solutions generated by~$S_{...
1994-08-26
2010-11-01
[ "gr-qc", "hep-th" ]
Jorma Louko
gr-qc/9408030
Maupertuis principle, Wheeler's superspace and an invariant criterion for local instability in general relativity
It is tempting to raise the issue of (metric) chaos in general relativity since the Einstein equations are a set of highly nonlinear equations which may exhibit dynamically very complicated solutions for the space-time metric. However, in general relativity it is not easy to construct indicators of chaos which are gaug...
1994-08-25
2009-09-25
[ "gr-qc" ]
Marek Biesiada and Svend E. Rugh
gr-qc/9408032
Gravitation and Cosmology in Generalized (1+1)-dimensional dilaton gravity
The actions of the ``$R=T$'' and string-inspired theories of gravity in (1+1) dimensions are generalized into one single action which is characterized by two functions. We discuss differing interpretations of the matter stress-energy tensor, and show how two such different interpretations can yield two different sets o...
1994-08-25
2010-04-06
[ "gr-qc" ]
J.S.F. Chan and R.B. Mann
gr-qc/9408031
Kaluza -- Klein Quantum Cosmology with Primordial Negative Cosmological Constant
In many interesting models, including superstring theories, a negative vacuum energy is predicted. Although this effect is usually regarded as undesirable from a cosmological point of view, we show that this can be the basis for a new approach to the cosmology of the early Universe. In the framework of quantum cosmolog...
1994-08-25
2007-05-23
[ "gr-qc" ]
E. I. Guendelman and A. B. Kaganovich
gr-qc/9408029
Quantum Behavior in Asymmetric, Weyl-Like Cartan Geometries
This discussion examines recent developments in the theory of a Weyl-like, Cartan geometry with natural Schr\"odinger field behavior proposed previously. In that model, very nearly exactly a coupled Einstein-Maxwell- Schr\"odinger, classical field theory emerges from a gauge invariant, purely geometric action based sol...
1994-08-24
2008-02-03
[ "gr-qc" ]
J.E. Rankin
gr-qc/9408028
New Algebraic Methods for Calculating the Heat Kernel and Effective Action in Quantum Gravity and Gauge Theories
An overview about recent progress in the calculation of the heat kernel and the one-loop effective action in quantum gravity and gauge theories is given. We analyse the general structure of the standard Schwinger-De Witt asymptotic expansion and discuss the applicability of that to the case of strongly curved manifolds...
1994-08-24
2007-05-23
[ "gr-qc", "hep-th" ]
I. G. Avramidi
gr-qc/9408027
What is and What should be Time?
The notions of time in the theories of Newton and Einstein are reviewed so that certain of their assumptions are clarified. These assumptions will be seen as the causes of the incompatibility between the two different ways of understanding time, and seen to be philosophical hypotheses, rather than purely scientific one...
1994-08-20
2008-02-03
[ "gr-qc" ]
Hitoshi Kitada and Lancelot R. Fletcher
gr-qc/9408024
Quantum cosmology and the value of $\Lambda$
We analyse a simple model with just a $\Lambda$ term present. Differing results are obtained depending on the boundary conditions applied. HH boundary conditions give the factor exp(1/Lambda) but in agreement with Rubakov et al. is badly behaved for negative lambda. Tunneling boundary conditions suggests a large initia...
1994-08-19
2009-10-22
[ "gr-qc" ]
D.H. Coule
gr-qc/9408026
Canonical measure and the flatness of a FRW universe
We consider the claim of Hawking and Page that the canonical measure applied to a FRW universe with a massive scalar field can solve the flatness problem regardless of inflation. By considering a general potential we are able to understand how the ambiguity for $\Omega$ found by Page in the $R^2$ theory is present when...
1994-08-19
2010-04-06
[ "gr-qc" ]
D.H. Coule
gr-qc/9408025
Inflationary cosmology with a non-analytic Lagrangian
We consider an alternative higher order gravity theory which is non-analytic in the Ricci curvature. It has power-law inflationary behaviour. This is further evidence that inflation is a general property of higher derivative gravity theories.
1994-08-19
2015-06-25
[ "gr-qc" ]
E. Bruning, D. Coule and C. Xu
gr-qc/9408021
Quantum State of Wormholes and Topological Arrow of Time
This paper studies the time-symmetry problem in quantum gravity. The issue depends critically on the choice of the quantum state and has been considered in this paper by restricting to the case of quantum wormholes. It is seen that pure states represented by a wave functional are time symmetric. However, a maximal anal...
1994-08-18
2014-11-17
[ "gr-qc" ]
Pedro F. Gonzalez-Diaz
gr-qc/9408023
The Theory of Everything vs the Theory of Anything
To what extent can our limited set of observations be used to pin down the specifics of a ``Theory of Everything''? In the limit where the links are arbitrarily tenuous, a ``Theory of Everything'' might become a ``Theory of Anything''. A clear understanding of what we can and can not expect to learn about the universe ...
1994-08-18
2018-05-02
[ "gr-qc", "astro-ph", "hep-th" ]
Andreas Albrecht
gr-qc/9408022
Wormholes and Cosmic Strings
A gravitational scenario is proposed where the euclidean action is invariant under the isotropic and homogeneous version of the euclidean {\it U(1)} group of local transformations of the scale factor and scalar matter field, interpreting the the trace of the second fundamental form as the gauge field. The model allows ...
1994-08-18
2007-05-23
[ "gr-qc" ]
Pedro F. Gonzalez-Diaz
gr-qc/9408020
On the stability of black hole event horizons
In this work we study a {\it gedanken} experiment constructed in order to test the cosmic censorship hypothesis and the second law of black hole thermo-dynamics. Matter with a negative gravitating energy is imagined added to a near extremal $U(1)$-charged static black hole in Einstein-Maxwell theory. The dynamics of a ...
1994-08-17
2009-10-22
[ "gr-qc" ]
Bjorn Jensen
gr-qc/9408019
Spontaneous excitation of an accelerated atom: The contributions of vacuum fluctuations and radiation reaction
We consider an atom in interaction with a massless scalar quantum field. We discuss the structure of the rate of variation of the atomic energy for an arbitrary stationary motion of the atom through the quantum vacuum. Our main intention is to identify and to analyze quantitatively the distinct contributions of vacuum ...
1994-08-16
2009-10-22
[ "gr-qc", "hep-th" ]
Juergen Audretsch and Rainer Mueller
gr-qc/9408018
Spherically Symmetric Event Horizons and Trapped Surfaces Developing {}from Innociuous Data
In this paper we show the existence of a large class of spherically symmetric data $d$ (on a spacelike hypersurface $S$), from which a perfect fluid spacetime (surrounded by vacuum) develops. This spacetime contains an event horizon (with trapped surfaces behind it). The data $d$ are regular and {\it innociuous}, i.e. ...
1994-08-15
2010-05-12
[ "gr-qc" ]
Ulrich Alfes and Henning M\"uller zum Hagen
gr-qc/9408017
Relevance of Induced Gauge Interactions in Decoherence
Decoherence in quantum cosmology is shown to occur naturally in the presence of induced geometric gauge interactions associated with particle production.A new 'gauge '-variant form of the semiclassical Einstein equations is also presented which makes the non-gravitating character of the vacuum polarisation energy expli...
1994-08-15
2011-08-04
[ "gr-qc" ]
Dhurjati Prasad Datta
gr-qc/9408016
Fluctuations of the Unruh Temperature
Using the influence functional formalism, the problem of an accelerating detector in the presence of a scalar field in its ground state is considered in Minkowski space. As is known since the work of Unruh, to a quantum mechanical detector following a definite, classical acceleration, the field appears to be thermally ...
1994-08-11
2011-08-04
[ "gr-qc", "hep-th" ]
J.-G. Demers
gr-qc/9408015
Observables for Two-Dimensional Black Holes
We consider the most general dilaton gravity theory in 1+1 dimensions. By suitably parametrizing the metric and scalar field we find a simple expression that relates the energy of a generic solution to the magnitude of the corresponding Killing vector. In theories that admit black hole solutions, this relationship lead...
1994-08-11
2016-08-24
[ "gr-qc" ]
J. Gegenberg, G. Kunstatter and D. Louis-Martinez