English
Related papers

Related papers: Tunneling in Anisotropic Cosmological Models

200 papers

We study the isotropisation of the homogeneous but anisotropic Bianchi class A models in presence of a minimally coupled and massive scalar field with or without a perfect fluid. To this end, we use the Hamiltonian formalism of Arnowitt,…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Stephane Fay

The tunneling Hamiltonian has proven to be a useful method in many body physics to treat particle tunneling between different states represented as wavefunctions. Here we apply a generalization of the way we formed appropriate wave…

Mathematical Physics · Physics 2007-05-23 A. W. Beckwith

The gauge usually adopted for extracting the reduced Hamiltonian of a thin spherical shell of matter in general relativity, becomes singular when dealing with two or more intersecting shells. We introduce here a more general class of gauges…

High Energy Physics - Theory · Physics 2008-11-26 Francesco Fiamberti , Pietro Menotti

The assisted tunneling of a wave packet between square one dimensional barriers is treated analytically. The tunneling rate is calculated exactly for a potential mimicking a constant electric field with arbitrary time dependence. The pole…

Quantum Physics · Physics 2015-05-13 G. Kalbermann

Understanding inhomogeneous and anisotropic fluid flows require mathematical and computational tools that are tailored to such flows and distinct from methods used to understand the canonical problem of homogeneous and isotropic turbulence.…

Fluid Dynamics · Physics 2023-01-05 J. B. Marston , S. M. Tobias

At the minisuperspace level of homogeneous models, the bare probability for a classical universe has a huge peak at small universes for the Hartle-Hawking `no-boundary' wavefunction, in contrast to the suppression at small universes for the…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Don N. Page

We study holographic entanglement entropy in spatially anisotropic field theory. We observe that for the background we consider in this paper, to a good approximation, the holographic entanglement entropy can be decomposed into two terms.…

High Energy Physics - Theory · Physics 2018-07-11 M. Rahimi , M. Ali-Akbari

Prompted by the longstanding interpretational controversy in quantum mechanics, quantum tunneling is heuristically addressed within the Everettian quantum multiverse. In this framework, the universal wavefunction splits into decohered…

Quantum Physics · Physics 2026-04-28 S. E. Ennadifi

Homogeneity is a crucial, but poorly tested, assumption in cosmology. We introduce a new approach which allows us to place limits on the presence of localized structures within essentially our entire observable volume, using cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-15 James. P. Zibin , Adam Moss

We use an extended version of the standard tunneling model to explain the anisotropic sound absorption in decagonal quasicrystals. The glassy properties are determined by an ensemble of two level systems (TLS), arbitrarily oriented. The TLS…

Materials Science · Physics 2012-10-09 Dragos-Victor Anghel , Dmitry V. Churochkin

Besides expanding anisotropically, the universe can also be anisotropic at the level of its (spatial) curvature. In particular, models with anisotropic curvature and isotropic expansion leads both to a $\Lambda$CDM-like phenomenology and to…

General Relativity and Quantum Cosmology · Physics 2017-11-17 Felipe O. Franco , Thiago S. Pereira

Anisotropic flows ($v_2$ and $v_4$) of hadrons and light nuclear clusters are studied by a partonic transport model and nucleonic transport model, respectively, in ultra-relativistic and intermediate energy heavy ion collisions. Both…

Nuclear Theory · Physics 2008-11-26 Y. G. Ma

We analyze quantum-mechanical counterpart of Newtonian cosmology and show that effects of zero-point motion eliminate classical density singularity. Quantum effects are particularly significant for closed Universes where without the…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Eugene B. Kolomeisky

The tunneling effect is the most popular phenomenon of quantum physics and is present in modern physical theories. Still, the most important features of this effect are already present in toy models - low dimensional quantum mechanics with…

Quantum Physics · Physics 2013-02-07 Zbigniew Ambrozinski

Tunneling half lives are obtained in a minimalistic deformation picture of nuclear decays. As widely documented in other deformation models, one finds that the effective mass of the nucleus changes with the deformation parameter. However,…

Nuclear Theory · Physics 2024-08-28 Samyak Jain , A. Bhagwat

A spatial point pattern is called anisotropic if its spatial structure depends on direction. Several methods for anisotropy analysis have been introduced in the literature. In this paper, we give an overview of nonparametric methods for…

Methodology · Statistics 2018-03-01 Tuomas Rajala , Claudia Redenbach , Aila Särkkä , Martina Sormani

In an undulant universe, cosmic expansion is characterized by alternating periods of acceleration and deceleration. We examine cosmologies in which the dark-energy equation of state varies periodically with the number of e-foldings of the…

Astrophysics · Physics 2009-11-11 Gabriela Barenboim , Olga Mena Requejo , Chris Quigg

A fundamental assumption in the standard model of cosmology is that the Universe is isotropic on large scales. Breaking this assumption leads to a set of solutions to Einstein's field equations, known as Bianchi cosmologies, only a subset…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-23 Daniela Saadeh , Stephen M. Feeney , Andrew Pontzen , Hiranya V. Peiris , Jason D. McEwen

A new method for analyzing point patterns produced by the evolution of gravitational clustering is presented. The method is taken from the study of molecular liquids, where it has been introduced for making a statistical description of…

Astrophysics · Physics 2009-10-31 R. Valdarnini

We consider tunneling of two interacting atoms with an even spatial symmetry. The atoms are prepared in two lowest excited states with respect to relative and center-of-mass motions. We observe monotonic and non-monotonic dependence of the…

Atomic Physics · Physics 2018-06-27 I. S. Ishmukhamedov , A. S. Ishmukhamedov