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Michael Maziashvili

Publications and source records attributed to Michael Maziashvili.

51 records · Page 3Linked to original sources
arXiv2006

Quantum fluctuations of braneworld background versus the TeV fundamental scale

Quantum fluctuations of gravitational field with respect to the ADD braneworld background turns out to be large enough spoiling the TeV scale physics as well. In view of this observation it becomes important to look for some protecting mechanism. The most natural such mechanism in the case of braneworld model with compactified extra dimensions can be the shape moduli of extra space. Quantum fluctuations of braneworld background affect significantly the production as well as evaporation of mini black holes studied very actively during the las few years. The enormous amplification of quantum fluctuations of the background space-time due to lowering the fundamental scale to the TeV range, is characteristic to other phenomenological braneworld models as well and correspondingly calls for attention.

hep-ph↗
arXiv2006

Quantum uncertainty in distance measurement: Holography and black hole thermodynamics

Exact conditions on the clock parameters corresponding to the minimal uncertainty in distance measurement are derived in uniform manner for any number of space time dimensions. The result espouses the holography principle no matter what the number of space time dimensions is. In this context the ADD braneworld model is considered. Some remarks are made on deviation of holography as well as of special relativity at the scales provided by the cosmological constant. We also comment on the potential influence of the background radiation on the uncertainty in length measurement. The presence of unavoidable quantum uncertainty in length measurement results in fluctuations of the black hole thermodynamics that can be interested to address the information loss problem. The quantum corrections to the black hole entropy obtained in various scenarios are imperceptible because of these fluctuations. At the Planck scale the fluctuations destroy the thermodynamic picture of the black hole.

hep-ph↗
arXiv2006

Black hole remnants due to GUP or quantum gravity?

Based on the micro-black hole \emph{gedanken} experiment as well as on general considerations of quantum mechanics and gravity the generalized uncertainty principle (GUP) is analyzed by using the running Newton constant. The result is used to decide between the GUP and quantum gravitational effects as a possible mechanism leading to the black hole remnants of about Planck mass.

gr-qc↗
arXiv2006

Particle escape into extra space

We focus on escape of a spin integer particle the challenge for which is of course that the corresponding field equation contains the second order time derivative and, in general, may be problematic for interpreting the extra-dimensional part of the field as a wave function for the KK modes as it is usually regarded.

hep-ph↗
arXiv2005

Dark matter in the framework of shell-universe

We show that the shell-universe model, used to explain the observed expansion rate of the universe without a dark energy component, provides also a natural mechanism for local increasing of the shell's tension leading to the modified Newton's law alternative to galactic dark matter.

astro-ph↗
arXiv2004

Brane solution with an increasing warp factor

We present a new brane solution in the (1+5)-dimensional space-time with an increasing warp factor, which localizes the zero modes of all kinds of matter fields and Newtonian gravity. The interesting features of this solution are: 1) In contrast to the Gogberashvili-Singleton case the effective wave function of the zero mode spinor field confined on the brane is finite at a position of brane; 2) There is exactly one zero mode for each matter field and the gravitational field confined on the brane with a finite probability and infinitely many zero modes (labelled by the angular momentum corresponding to extra space) are located in the bulk at different localization radii.

hep-ph↗
arXiv2003

Particle production by the expanding thin-walled bubble

Neglecting the effect of particle production at the moment of bubble nucleation, the spectrum of created particles during the bubble expansion is evaluated in the thin-wall approximation. It is shown that the expanding thin-walled bubble makes the dominant contribution to the particle production.

hep-th↗
arXiv2003

Particle production by the thick-walled bubble

The spectrum of created particles during the tunneling process, leading to the decay of a false vacuum state, is studied numerically in the thick-wall approximation. It is shown that in this case the particle production is very intensive for small momenta. The number of created particles is nearly constant $n(p)\approx 1$ for $4\leq p\leq500$.

hep-th↗
arXiv2003

Proper fluctuations associated with quantum tunneling in field theory

It is shown that, to the lowest order in $\hbar,$ the particle production related to the tunneling that leads to the false vacuum decay is described by the orthogonal part of fluctuation field with respect to the bounce solution. As a simple example the spatially homogeneous tunneling is considered in order to illustrate the consequences coming from such a restriction of the fluctuation field.

hep-th↗
arXiv2003

Particle production related to the tunneling in false vacuum decay

Motivated by the work of Mersini, the particle production related to the tunneling in false vacuum decay is carefully investigated in the thin-wall approximation. It is shown that in this case the particle production is exponentially suppressed even when the momentum is comparable to the curvature scale of the bubble. The number of created particles is ultraviolet finite.

hep-th↗
arXiv2002

Uniqueness of a Negative Mode About a Bounce Solution

We consider the uniqueness problem of a negative eigenvalue in the spectrum of small fluctuations about a bounce solution in a multidimensional case. Our approach is based on the concept of conjugate points from Morse theory and is a natural generalization of the nodal theorem approach usually used in one dimensional case. We show that bounce solution has exactly one conjugate point at $τ=0$ with multiplicity one.

hep-th↗