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Related papers: Vacuum currents in elliptic pseudosphere tubes

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We study the appearance and specific properties of the structures in the local Universe by means of the Vlasov kinetic technique. We consider the role of the cosmological constant in local structure formation via the theorem on the general…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-08 V. G. Gurzadyan , N. N. Fimin , V. M. Chechetkin

In this paper, we study the discrete classical phase space of loop gravity, which is expressed in terms of the holonomy-flux variables, and show how it is related to the continuous phase space of general relativity. In particular, we prove…

General Relativity and Quantum Cosmology · Physics 2013-04-04 Laurent Freidel , Marc Geiller , Jonathan Ziprick

In this work, we investigate the dynamics of bulk viscous models with decaying vacuum energy density (VED) in a spatially homogeneous and isotropic flat Friedmann-Lema\^{i}tre- Robertson-walker (FLRW) spacetime. We particularly are…

General Relativity and Quantum Cosmology · Physics 2024-01-10 C. P. Singh , Vinita Khatri

We study structure formation in the late Universe within the Vlasov kinetic self-consistent field approach. Our work is principally focused on the use of the modified gravitational potential with a repulsive term of the cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-28 V. G. Gurzadyan , N. N. Fimin , V. M. Chechetkin

Heisenberg-like spins lying on the pseudosphere (a 2-dimensional infinite space with constant negative curvature) cannot give rise to stable soliton solutions. Only fractional solutions can be stabilized on this surface provided that at…

Strongly Correlated Electrons · Physics 2009-11-11 L. R. A. Belo , N. M. Oliveira-Neto , W. A. Moura-Melo , A. R. Pereira , E. Ercolessi

We show that the vacuum energy of a free quantized field of very low mass can significantly alter the recent expansion of the universe. The effective action of the theory is obtained from a non-perturbative sum of scalar curvature terms in…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Leonard Parker , Alpan Raval

Vector displacements expressed in spherical coordinates are proposed. They correspond to electromagnetic fields in vacuum that globally rotate about an axis and display many circular patterns on the surface of a sphere. The fields basically…

Classical Physics · Physics 2021-06-11 Daniele Funaro

In this paper, we investigate the fermionic current densities induced by a magnetic flux running along the idealized cosmic string in a four-dimensional spacetime, admitting that the coordinate along the string's axis is compactified. In…

High Energy Physics - Theory · Physics 2013-08-29 E. R. Bezerra de Mello , A. A. Saharian

Flow-induced vibration (FIV) commonly occurs in rigidly coupled twin-pipe structures. However, the limited understanding of their FIV responses and hydrodynamic features presents a major challenge to the development of reliable engineering…

Fluid Dynamics · Physics 2025-06-09 Jiawei Shen , Shixiao Fu , Xuepeng Fu , Torgeir Moan , Svein Sævik

We study the Casimir vacuum energy density and the Casimir pressure for a massless scalar field confined between two nearby parallel plates in a slightly curved, static spacetime background, employing the weak field approximation in the…

General Relativity and Quantum Cosmology · Physics 2017-04-19 G. Lambiase , A. Stabile , An. Stabile

Whightman function, vacuum expectation values of the field square, and the energy-momentum tensor are investigated for a scalar field inside a wedge with and without a coaxial cylindrical boundary. Dirichlet boundary conditions are assumed…

High Energy Physics - Theory · Physics 2009-11-11 A. A. Saharian , A. S. Tarloyan

We investigate the vacuum expectation value of a complex scalar field on a two-dimensional torus with quantized magnetic flux $M$. A characteristic feature of this system is the emergence of a critical area: when the area of the torus…

High Energy Physics - Theory · Physics 2026-04-27 Mayumi Akamatsu , Hiroki Imai , Makoto Sakamoto , Maki Takeuchi

One of the central difficulties of settling the $L^2$-bounded curvature conjecture for the Einstein -Vacuum equations is to be able to control the causal structure of spacetimes with such limited regularity. In this paper we show how to…

Analysis of PDEs · Mathematics 2016-09-07 Sergiu Klainerman , Igor Rodnianski

We interpret as shear viscosity the anisotropic pressure that emerges in inhomogeneous spherically symmetric spacetimes described by the Lemaitre-Tolman-Bondi (LTB) metric in a comoving frame. By assuming that local isotropic pressure and…

General Relativity and Quantum Cosmology · Physics 2008-12-24 Roberto A Sussman

We present a summary of the main results within the Scale Invariant Vacuum (SIV) paradigm based on the Weyl Integrable Geometry (WIG) as an extension to the standard Einstein General Relativity (EGR). After a brief review of the…

General Relativity and Quantum Cosmology · Physics 2024-06-03 Vesselin G. Gueorguiev , Andre Maeder

We relate physical time with the topology of magnetic field vortices. We base ourselves on a formulation of unimodular gravity where the cosmological constant $\Lambda$ appears as the canonical dual to a variable which on-shell becomes…

High Energy Physics - Theory · Physics 2024-06-24 Altay Etkin , João Magueijo , Farbod-Sayyed Rassouli

The Casimir effect for general Robin conditions on the surface of a cylinder in $D$-spacetime dimensions is studied for massive scalar field with general curvature coupling. The energy distribution and vacuum stress are investigated. We…

High Energy Physics - Theory · Physics 2009-11-07 August Romeo , Aram A. Saharian

We investigate vacuum expectation value of the energy-momentum tensor for a massive Dirac field in flat spacetime with a toroidal subspace of a general dimension. Quasiperiodicity conditions with arbitrary phases are imposed on the field…

High Energy Physics - Theory · Physics 2024-08-09 A. A. Saharian , R. M. Avagyan , G. H. Harutyunyan , G. H. Nikoghosyan

In this paper, we study the Casimir effect in a curved spacetime described by gravitational actions quadratic in the curvature. In particular, we consider the dynamics of a massless scalar field confined between two nearby plates and…

General Relativity and Quantum Cosmology · Physics 2019-02-04 Luca Buoninfante , Gaetano Lambiase , Luciano Petruzziello , Antonio Stabile

The linear cosmological perturbation theory of an almost homogeneous and isotropic perfect fluid universe is reconsidered and formally simplified by introducing new covariant and gauge-invariant variables with physical interpretations on…

General Relativity and Quantum Cosmology · Physics 2011-07-19 Winfried Zimdahl