2,581 research outputs found
Non-Unitary and Unitary Transitions in Generalized Quantum Mechanics, New Small Parameter and Information Problem Solving
Quantum Mechanics of the Early Universe is considered as deformation of a
well-known Quantum Mechanics. Similar to previous works of the author, the
principal approach is based on deformation of the density matrix with
concurrent development of the wave function deformation in the respective
Schr{\"o}dinger picture, the associated deformation parameter being interpreted
as a new small parameter. It is demonstrated that the existence of black holes
in the suggested approach in the end twice causes nonunitary transitions
resulting in the unitarity. In parallel this problem is considered in other
terms: entropy density, Heisenberg algebra deformation terms, respective
deformations of Statistical Mechanics, - all showing the identity of the basic
results. From this an explicit solution for Hawking's informaion paradox has
been derived.Comment: 18 page
Extended uncertainty principle and the geometry of (anti)-de Sitter space
It has been proposed that on (anti)-de Sitter background, the Heisenberg
uncertainty principle should be modified by the introduction of a term
proportional to the cosmological constant. We show that this modification of
the uncertainty principle can be derived straightforwardly from the geometric
properties of (anti)-de Sitter spacetime. We also discuss the connection
between the so-called extended generalized uncertainty principle and triply
special relativity.Comment: 8 pages, plain TeX, references adde
Strongly Scale-dependent Non-Gaussianity
We discuss models of primordial density perturbations where the
non-Gaussianity is strongly scale-dependent. In particular, the non-Gaussianity
may have a sharp cut-off and be very suppressed on large cosmological scales,
but sizeable on small scales. This may have an impact on probes of
non-Gaussianity in the large-scale structure and in the cosmic microwave
background radiation anisotropies.Comment: 4 page
Instanton-induced contributions to structure functions of deep inelastic scattering
We identify and calculate the instanton-induced contributions to deep
inelastic scattering which correspond to nonperturbative exponential
corrections to the coefficient functions in front of parton distributions of
the leading twist.Comment: MPI-Ph/92-89 , LATEX, 15 pages, 3 figures incl. as uu-encoded fil
Pilot Wave model that includes creation and annihilation of particles
The purpose of this paper is to come up with a Pilot Wave model of quantum
field theory that incorporates particle creation and annihilation without
sacrificing determinism. This has been previously attempted in an article by
the same author titled "Incorporating particle creation and annihilation in
Pilot Wave model", in a much less satisfactory way. In this paper I would like
to "clean up" some of the things. In particular, I would like to get rid of a
very unnatural concept of "visibility" of particles, which makes the model much
simpler. On the other hand, I would like to add a mechanism for decoherence,
which was absent in the previous version.Comment: 9 pages, no figure
Symmetry breaking aspects of the effective Lagrangian for quantum black holes
The physical excitations entering the effective Lagrangian for quantum black
holes are related to a Goldstone boson which is present in the Rindler limit
and is due to the spontaneous breaking of the translation symmetry of the
underlying Minkowski space. This physical interpretation, which closely
parallels similar well-known results for the effective stringlike description
of flux tubes in QCD, gives a physical insight into the problem of describing
the quantum degrees of freedom of black holes. It also suggests that the
recently suggested concept of 'black hole complementarity' emerges at the
effective Lagrangian level rather than at the fundamental level.Comment: 11 pages, Latex,1 figur
Wave Packets Propagation in Quantum Gravity
Wave packet broadening in usual quantum mechanics is a consequence of
dispersion behavior of the medium which the wave propagates in it. In this
paper, we consider the problem of wave packet broadening in the framework of
Generalized Uncertainty Principle(GUP) of quantum gravity. New dispersion
relations are derived in the context of GUP and it has been shown that there
exists a gravitational induced dispersion which leads to more broadening of the
wave packets. As a result of these dispersion relations, a generalized
Klein-Gordon equation is obtained and its interpretation is given.Comment: 9 pages, no figur
Non-Gaussian Halo Bias Re-examined: Mass-dependent Amplitude from the Peak-Background Split and Thresholding
Recent results of N-body simulations have shown that current theoretical
models are not able to correctly predict the amplitude of the scale-dependent
halo bias induced by primordial non-Gaussianity, for models going beyond the
simplest, local quadratic case. Motivated by these discrepancies, we carefully
examine three theoretical approaches based on (1) the statistics of thresholded
regions, (2) a peak-background split method based on separation of scales, and
(3) a peak-background split method using the conditional mass function. We
first demonstrate that the statistics of thresholded regions, which is shown to
be equivalent at leading order to a local bias expansion, cannot explain the
mass-dependent deviation between theory and N-body simulations. In the two
formulations of the peak-background split on the other hand, we identify an
important, but previously overlooked, correction to the non-Gaussian bias that
strongly depends on halo mass. This new term is in general significant for any
primordial non-Gaussianity going beyond the simplest local fNL model. In a
separate paper, we compare these new theoretical predictions with N-body
simulations, showing good agreement for all simulated types of non-Gaussianity.Comment: 26 pages, 3 figures (v2): minor changes from (v1). matches published
versio
Sensitivity of spherical gravitational-wave detectors to a stochastic background of non-relativistic scalar radiation
We analyze the signal-to-noise ratio for a relic background of scalar
gravitational radiation composed of massive, non-relativistic particles,
interacting with the monopole mode of two resonant spherical detectors. We find
that the possible signal is enhanced with respect to the differential mode of
the interferometric detectors. This enhancement is due to: {\rm (a)} the
absence of the signal suppression, for non-relativistic scalars, with respect
to a background of massless particles, and {\rm (b)} for flat enough spectra, a
growth of the signal with the observation time faster than for a massless
stochastic background.Comment: four pages, late
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