248 research outputs found
Penrose Diagram for a Transient Black Hole
A Penrose diagram is constructed for a spatially coherent black hole that
smoothly begins an accretion, then excretes symmetrically as measured by a
distant observer, with the initial and final states described by a metric of
Minkowski form. Coordinate curves on the diagram are computationally derived.
Causal relationships between space-time regions are briefly discussed. The life
cycle of the black hole demonstrably leaves asymptotic observers in an
unaltered Minkowski space-time of uniform conformal scale.Comment: 14 pages, 9 figures, spelling correction
Construction of Non-Perturbative, Unitary Particle-Antiparticle Amplitudes for Finite Particle Number Scattering Formalisms
Starting from a unitary, Lorentz invariant two-particle scattering amplitude
, we show how to use an identification and replacement process to construct a
unique, unitary particle-antiparticle amplitude. This process differs from
conventional on-shell Mandelstam s,t,u crossing in that the input and
constructed amplitudes can be off-diagonal and off-energy shell. Further,
amplitudes are constructed using the invariant parameters which are appropriate
to use as driving terms in the multi-particle, multichannel non-perturbative,
cluster decomposable, relativistic scattering equations of the Faddeev-type
integral equations recently presented by Alfred, Kwizera, Lindesay and Noyes.
It is therefore anticipated that when so employed, the resulting multi-channel
solutions will also be unitary. The process preserves the usual
particle-antiparticle symmetries. To illustrate this process, we construct a
J=0 scattering length model chosen for simplicity. We also exhibit a class of
physical models which contain a finite quantum mass parameter and are Lorentz
invariant. These are constructed to reduce in the appropriate limits, and with
the proper choice of value and sign of the interaction parameter, to the
asymptotic solution of the non-relativistic Coulomb problem, including the
forward scattering singularity, the essential singularity in the phase, and the
Bohr bound-state spectrum
Self-consistent solutions of canonical proper self-gravitating quantum systems
Generic self-gravitating quantum solutions that are not critically dependent
on the specifics of microscopic interactions are presented. The solutions
incorporate curvature effects, are consistent with the universality of gravity,
and have appropriate correspondence with Newtonian gravitation. The results are
consistent with known experimental results that indicate the maintenance of the
quantum coherence of gravitating systems, as expected through the equivalence
principle.Comment: 13 pages, 7 figure
Black Hole - Never Forms, or Never Evaporates
Many discussion about the black hole conundrums, such as singularity and
information loss, suggested that there must be some essential irreconcilable
conflict between quantum theory and classical gravity theory, which cannot be
solved with any semiclassical quantized model of gravity, the only feasible way
must be some complete unified quantum theory of gravity.
In \cite{Vachaspati2007a}, the arguments indicate the possibility of an
alternate outcome of gravitational collapse which avoids the information loss
problem. In this paper, also with semiclassical analysis, it shows that so long
as the mechanism of black hole evaporation satisfies a quite loose condition
that the evaporation lifespan is finite for external observers, regardless of
the detailed mechanism and process of evaporation, the conundrums above can be
naturally avoided. This condition can be satisfied with Hawking-Unruh
mechanism. Thus, the conflict between quantum theory and classical gravity
theory may be not as serious as it seemed to be, the effectiveness of
semiclassical methods might be underestimated.
An exact universal solution with spherical symmetry of Einstein field
equation has been derived in this paper. All possible solutions with spherical
symmetry of Einstein field equation are its special cases.
In addition, some problems of the Penrose diagram of an evaporating black
hole first introduced by Hawking in 1975 \cite{Hawking1975} are clarified.Comment: 17 pages, 7 figures. Compared to the published version in JCAP, some
minimal typeset error has been correcte
Minimal relativistic three-particle equations
A minimal self-consistent set of covariant and unitary three-particle equations is presented. Numerical results are obtained for three-particle bound states, elastic scattering and rearrangement of bound pairs with a third particle, and amplitudes for breakup into states of three free particles. The mathematical form of the three-particle bound state equations is explored; constraints are set upon the range of eigenvalues and number of eigenstates of these one parameter equations. The behavior of the number of eigenstates as the two-body binding energy decreases to zero in a covariant context generalizes results previously obtained non-relativistically by V. Efimov
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