45 research outputs found
Inverse Square Law of Gravitation in (2+1)-Dimensional Space-Time as a Consequence of Casimir Energy
The gravitational effect of vacuum polarization in space exterior to a
particle in (2+1)-dimensional Einstein theory is investigated. In the weak
field limit this gravitational field corresponds to an inverse square law of
gravitational attraction, even though the gravitational mass of the quantum
vacuum is negative. The paradox is resolved by considering a particle of finite
extension and taking into account the vacuum polarization in its interior.Comment: 10 pages, LaTeX, Report: UPR-0540-T, To appear in Physica Script
Self-Dual Chern-Simons Solitons in (2+1)-Dimensional Einstein Gravity
We consider here a generalization of the Abelian Higgs model in curved space,
by adding a Chern--Simons term. The static equations are self-dual provided we
choose a suitable potential. The solutions give a self-dual
Maxwell--Chern--Simons soliton that possesses a mass and a spin
Physical States of the Quantum Conformal Factor
The conformal factor of the spacetime metric becomes dynamical due to the
trace anomaly of matter fields. Its dynamics is described by an effective
action which we quantize by canonical methods on the Einstein universe . We find an infinite tower of discrete states which satisfy the
constraints of quantum diffeomorphism invariance. These physical states are in
one-to-one correspondence with operators constructed by integrating integer
powers of the Ricci scalar.Comment: PlainTeX File, 34 page
Exact Relativistic Two-Body Motion in Lineal Gravity
We consider the N-body problem in (1+1) dimensional lineal gravity. For 2
point masses (N=2) we obtain an exact solution for the relativistic motion. In
the equal mass case we obtain an explicit expression for their proper
separation as a function of their mutual proper time. Our solution gives the
exact Hamiltonian to infinite order in the gravitational coupling constant.Comment: latex, 11 pages, 2 figures, final version to appear in Phys. Rev.
Let
Vortices in Bogomol'nyi Limit of Einstein Maxwell Higgs Theory with or without External Sources
The Abelian Higgs model with or without external particles is considered in
curved space. Using the dual transformation, we rewrite the model in terms of
dual gauge fields and derive the Bogomol'nyi-type bound. We examine
cylindrically symmetric solutions to Einstein equations and the first-order
Bogomol'nyi equations, and find vortex solutions and vortex-particle composites
which lie on the spatial manifold with global geometry described by a cylinder
asymptotically or a two sphere in addition to the well-known cone.Comment: LaTeX, 23 pages, 10 LaTeX figures included, KHTP-93-05, SNUTP-93-100,
DPNU-93-46. (A note and several references added
Entropy generation in 2+1-dimensional Gravity
The tunneling approach, for entropy generation in quantum gravity, is shown
to be valid when applied to 3-D general relativity. The entropy of de Sitter
and Reissner-Nordstr\"om external event horizons and of the 3-D black hole
obtained by Ba\~nados et. al. is rederived from tunneling of the metric to
these spacetimes. The analysis for spacetimes with an external horizon is
carried out in a complete analogy with the 4-D case. However, we find
significant differences for the black hole. In particular the initial
configuration that tunnels to a 3-D black hole may not to yield an infinitely
degenerate object, as in 4-D Schwarzschild black hole. We discuss the possible
relation to the evaporation of the 3-D black hole.Comment: 22 pages, Tex, TAUP-2102-9
Thermodynamics and Evaporation of the 2+1-D Black Hole
The properties of canonical and microcanonical ensembles of a black hole with
thermal radiation and the problem of black hole evaporation in 3-D are studied.
In 3-D Einstein-anti-de Sitter gravity we have two relevant mass scales,
, and , which are particularly relevant
for the evaporation problem. It is argued that in the `weak coupling' regime
, the end point of an evaporating black hole formed
with an initial mass , is likely to be a stable remnant in equilibrium
with thermal radiation. The relevance of these results for the information
problem and for the issue of back reaction is discussed. In the `strong
coupling' regime, a full fledged quantum gravity
treatment is required. Since the total energy of thermal states in anti-de
Sitter space with reflective boundary conditions at spatial infinity is bounded
and conserved, the canonical and microcanonical ensembles are well defined. For
a given temperature or energy black hole states are locally stable. In the weak
coupling regime black hole states are more probable then pure radiation states.Comment: 11 pages, TAUP 2141/94, Late
Aspects of classical and quantum motion on a flux cone
Motion of a non-relativistic particle on a cone with a magnetic flux running
through the cone axis (a ``flux cone'') is studied. It is expressed as the
motion of a particle moving on the Euclidean plane under the action of a
velocity-dependent force. Probability fluid (``quantum flow'') associated with
a particular stationary state is studied close to the singularity,
demonstrating non trivial Aharonov-Bohm effects. For example, it is shown that
near the singularity quantum flow departs from classical flow. In the context
of the hydrodynamical approach to quantum mechanics, quantum potential due to
the conical singularity is determined and the way it affects quantum flow is
analysed. It is shown that the winding number of classical orbits plays a role
in the description of the quantum flow. Connectivity of the configuration space
is also discussed.Comment: LaTeX file, 21 pages, 8 figure
Heuristic Models of Two-Fermion Relativistic Systems with Field-Type Interaction
We use the chain of simple heuristic expedients to obtain perturbative and
exactly solvable relativistic spectra for a family of two-fermionic bound
systems with Coulomb-like interaction. In the case of electromagnetic
interaction the spectrum coincides up to the second order in a coupling
constant with that following from the quantum electrodynamics. Discrepancy
occurs only for S-states which is the well-known difficulty in the bound-state
problem. The confinement interaction is considered too.
PACS number(s): 03.65.Pm, 03.65.Ge, 12.39.PnComment: 16 pages, LaTeX 2.0