Fri - 08/20/21

There is no new related paper today

There is no new related paper today

  1. [2108.08438] - Testing the equivalence principle and discreteness of spacetime through the $t^3$ gravitational phase with quantum information technology - Fabrizio Tamburini, Ignazio Licata

  2. [2108.08308] - Product of Random States and Spatial (Half-)Wormholes - Kanato Goto, Yuya Kusuki, Kotaro Tamaoka, Tomonori Ugajin

  3. [2108.08322] - Fractons and exotic symmetries from branes - Hao Geng, Shamit Kachru, Andreas Karch, Richard Nally, Brandon C. Rayhaun

Thu - 08/19/21

There is no new related paper today

There is no new related paper today

  1. [2108.07912] - Schwarzschild-like Wormholes in Asymptotically Safe Gravity - M.Nilton, G. Alencar

  2. [2108.07824] - Schrödinger evolution of two-dimensional black holes - Steven B. Giddings

  3. [2108.07986] - Tests of Standard Cosmology in Horava Gravity - Nils A. Nilsson, Mu-In Park

Wed - 08/18/21

A Brief Overview of Results about Uniqueness of the Quantization in Cosmology

  • Authors: Jerónimo Cortez, Guillermo A. Mena Marugán, José M. Velhinho
  • Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
  • Arxiv link: https://arxiv.org/abs/2108.07489
  • Abstract The purpose of this review is to provide a brief overview of some recent conceptual developments about possible criteria to guarantee the uniqueness of the quantization in a variety of situations that are found in cosmological systems. These criteria impose some conditions on the representation of a group of physically relevant linear transformations. Generally, this group contains any existing symmetry of the spatial sections. These symmetries may or may not be sufficient for the purpose of uniqueness and may have to be complemented with other remaining symmetries that affect the time direction, or with dynamical transformations that in fact are not symmetries. We discuss the extent to which a unitary implementation of the resulting group suffices to fix the quantization, a demand that can be seen as a weaker version of the requirement of invariance. In particular, a strict invariance under certain transformations may eliminate some physically interesting possibilities in the passage to the quantum theory. This is the first review in which this unified perspective is adopted to discuss otherwise rather different uniqueness criteria proposed either in homogeneous loop quantum cosmology or in the Fock quantization of inhomogeneous cosmologies.

There is no new related paper today

  1. [2108.07607] - Potential consequences of wormhole-mediated entanglement - Edward Wilson-Ewing

  2. [2108.07766] - Nonlinear electrodynamics effects on the black hole shadow, deflection angle, quasinormal modes and greybody factors - Mert Okyay, Ali Övgün

Tue - 08/17/21

Loop quantum gravity with optimal control path integral, and application to black hole tunneling

  • Authors: Quentin Ansel
  • Subjects: General Relativity and Quantum Cosmology (gr-qc); Quantum Physics (quant-ph)
  • Arxiv link: https://arxiv.org/abs/2108.07023
  • Abstract This paper presents a novel path integral formalism for Einstein’s theory of gravitation from the viewpoint of optimal control theory. Despite its close relation to the well-known variational principles of physicists, optimal control turns out to be more general. Within this context, a Lagrangian different from the Einstein-Hilbert Lagrangian is defined. Einstein field equations are recovered exactly with variations of the new action functional. The quantum theory is obtained using Ashtekar variables and the loop scalar product. By means of example, the tunneling process of a black hole into another black hole or into a white hole is investigated with a toy model.

There is no new related paper today

  1. [2108.06470] - Absorption cross section of regular black holes in scalar-tensor conformal gravity - Yang Li, Yan-Gang Miao

  2. [2108.06824] - Quantum Gravitational Corrections to the Entropy of a Schwarzschild Black Hole - Xavier Calmet, Folkert Kuipers

  3. [2108.07182] - On the Superconformal Index of Chern-Simons theories and their KK Spectrometry - Hyojoong Kim, Nakwoo Kim

Mon - 08/16/21

Initial conditions of pre-inflation with Hilltop potential in loop quantum cosmology

  • Authors: M. Shahalam, Kuralay Yesmakhanova, Zhanar Umurzakhova
  • Subjects: General Relativity and Quantum Cosmology (gr-qc)
  • Arxiv link: https://arxiv.org/abs/2108.06218
  • Abstract In this paper, we investigate the dynamics of pre-inflation with Hilltop potential in the framework of loop quantum cosmology. The initial conditions of inflaton field at the quantum bounce is categorized into two classes, first one is dominated by kinetic energy and second one by potential energy. In both cases, the physically viable initial values of inflaton field at the bounce are obtained numerically that generate the desired slow-roll inflation and also sufficient number of $e$-folds. To be consistent with observations at least 60 $e$-folds are required. In case of kinetic energy dominated initial conditions of inflaton field at the bounce, the numerical evolution of the background prior to preheating is divided into three different regions: {\it bouncing, transition and slow-roll inflation} whereas bouncing and transition phases disappear in the potential energy dominated case but still slow-roll inflation is achieved. This is true in case of $p=4$ and $v=1 M_{Pl}$ of Hilltop potential. However for other cases, slow-roll inflation can not be obtained. Moreover, we study the phase space analysis for Hilltop potential and discuss the phase space trajectories under the chosen parameters.

There is no new related paper today

  1. [2108.06294] - Ghosts without runaway - Cédric Deffayet, Shinji Mukohyama, Alexander Vikman

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