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Related papers: Lump-like Structures in Scalar-field Models

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Several isotropic, homogeneous cosmological models containing a self-interacting minimally coupled scalar field, a perfect fluid source and cosmological constant are solved. New exact, asymptotically stable solutions with an inflationary…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Luis P. Chimento , Alejandro S. Jakubi

We consider a zero-temperature one-dimensional system of bosons interacting via the soft-shoulder potential in the continuum, typical of dressed Rydberg gases. We employ quantum Monte Carlo simulations, which allow for the exact calculation…

We use the conformal method to obtain solutions of the Einstein-scalar field gravitational constraint equations. Handling scalar fields is a bit more challenging than handling matter fields such as fluids, Maxwell fields or Yang-Mills…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Yvonne Choquet-Bruhat , James Isenberg , Daniel Pollack

In this short review, we discuss recent advances in exact solutions of models based on a one- dimensional (1D) Coulomb gas by means of field-theoretic functional integral methods. The exact solutions can be used to assess the accuracy of…

Statistical Mechanics · Physics 2012-09-18 Ronald R. Horgan , David S. Dean , Vincent Démery , Thomas C. Hammant , Ali Naji , Rudolf Podgornik

The shape of the local bubble is modeled in the framework of the thin layer approximation. The asymmetric shape of the local bubble is simulated by introducing axial profiles for the density of the interstellar medium, such as exponential,…

Astrophysics of Galaxies · Physics 2020-02-10 Lorenzo Zaninetti

This paper constructs continuously self-similar solution of a spherically symmetric gravitational collapse of a scalar field in n dimensions. The qualitative behavior of these solutions is explained, and closed-form answers are provided…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Andrei V. Frolov

Motivated by the recent interest in the criticality of open quantum many-body systems, we study nonlinear sigma models with complexified couplings as a general framework for nonunitary field theory. Applying the perturbative…

Statistical Mechanics · Physics 2026-01-29 Kazuki Yamamoto , Kohei Kawabata

We analyse shapes of overdense regions (clusters and superclusters) in controlled N-body simulations of gravitational clustering with power law initial spectra P(k) \propto k^n, n = -3, -2, -1, 0. At values of the density just above the…

Astrophysics · Physics 2009-10-30 B. S. Sathyaprakash , Varun Sahni , Sergei F. Shandarin

We consider the lagrangian of a self-interacting complex scalar field admitting generically Q-balls solutions. This model is extended by minimal coupling to electromagnetism and to gravity. A stationnary, axially-symmetric ansatz for the…

General Relativity and Quantum Cosmology · Physics 2009-07-07 Y. Brihaye , Th. Caebergs , T. Delsate

A relativistic topological insulator model in three spatial dimensions which is a non trivial extension of the non-abelian Landau problem is proposed. The model is exactly soluble and energy levels have both a discrete and a continuous…

High Energy Physics - Theory · Physics 2021-12-17 J. Gamboa , F. Mendez

We present a general numerical approach to solve the equations for bubble wall profiles in models with more than one scalar field and CP violating phases. We discuss the algorithm as well as several problems associated with it and show some…

High Energy Physics - Phenomenology · Physics 2009-10-31 P. John

We study a spherical, self-gravitating fluid model, which finds applications in cosmic structure formation. We argue that since the system features nonlinearity and gravity-induced dispersion, the emergence of solitons becomes possible. We…

Pattern Formation and Solitons · Physics 2024-02-21 G. N. Koutsokostas , S. Sypsas , O. Evnin , T. P. Horikis , D. J. Frantzeskakis

We investigate cosmological models with a free scalar field and a viscous fluid. We find exact solutions for a linear and nonlinear viscosity pressure. Both yield singular and bouncing solutions. In the first regime, a de Sitter stage is…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Luis P. Chimento , Alejandro S. Jakubi

Q-balls are non-topological solitons arising in scalar field theories. Solutions for rotating Q-balls (and the related boson stars) have been shown to exist when the angular momentum is equal to an integer multiple of the Q-ball charge $Q$.…

High Energy Physics - Theory · Physics 2024-04-11 Yahya Almumin , Julian Heeck , Arvind Rajaraman , Christopher B. Verhaaren

Algorithms are developed for generating a class of exact braneworld cosmologies, where a self-interacting scalar field is confined to a positive-tension brane embedded in a bulk containing a negative cosmological constant. It is assumed…

General Relativity and Quantum Cosmology · Physics 2009-12-31 Rachael M. Hawkins , James E. Lidsey

We consider cosmological models based on the scalar-torsion gravity implying non-minimal coupling between torsion and the scalar field with certain relations between model's parameters. Based on observational constraints on the values of…

General Relativity and Quantum Cosmology · Physics 2024-11-14 I. V. Fomin , S. V. Chervon , E. S. Dentsel

With this paper, we gain a better understanding of the set of near-field structures on a fixed scalar group. If we were able to describe all near-field structures on a fixed scalar group, we could describe all near-vector spaces. The…

Rings and Algebras · Mathematics 2022-11-21 Sophie Marques , Leandro Boonzaaier

We present $N$-body cosmlogical simulations in the framework of the Newtonian limit of scalar-tensor theories of gravity. The scalar field is described by a modified Helmholtz equation with a source that is coupled to the standard Poisson…

Astrophysics · Physics 2009-06-23 M. A. Rodriguez-Meza

Quantum many-body systems exhibit an extremely diverse range of phases and physical phenomena. Here, we prove that the entire physics of any other quantum many-body system is replicated in certain simple, "universal" spin-lattice models. We…

Quantum Physics · Physics 2019-10-07 Toby Cubitt , Ashley Montanaro , Stephen Piddock

We propose new braneworld models arising from a scalar field in the bulk. In these examples, the induced on--brane line element is de Sitter (or anti de Sitter) and the bulk (five dimensional) Einstein equations can be exactly solved to…

High Energy Physics - Theory · Physics 2009-05-05 Supratik Pal , Sayan Kar