scholarly journals Massive Spin Zero Fields in Cosmology and the Tail-Free Property

Symmetry ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 36 ◽  
Author(s):  
Valerio Faraoni
Keyword(s):  
Scalar Field ◽  
Cosmological Constant ◽  
Wave Equations ◽  
Coupling Constant ◽  
De Sitter ◽  
Field Mass ◽  
Curved Space ◽  
Inflaton Field ◽  
Massive Spin ◽  
Huygens Principle

Fields of spin s ≥ 1 / 2 satisfying wave equations in a curved space obey the Huygens principle under certain conditions clarified by a known theorem. Here, this theorem is generalized to spin zero and applied to an inflaton field in de Sitter-like space, showing that tails of scalar radiation are an unavoidable physical feature. Requiring the absence of tails, on the contrary, necessarily implies an unnatural tuning between cosmological constant, scalar field mass, and coupling constant to the curvature.

scholarly journals Massive scalar field perturbation on Kerr black holes in dynamical Chern–Simons gravity

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
Shao-Jun Zhang
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Scalar Field ◽  
Massive Scalar ◽  
Coupling Constant ◽  
Field Mass ◽  
Field Perturbation ◽  
Massive Scalar Field ◽  
Kerr Black Holes ◽  
Chern Simons

AbstractWe study massive scalar field perturbation on Kerr black holes in dynamical Chern–Simons gravity by performing a $$(2+1)$$ ( 2 + 1 ) -dimensional simulation. Object pictures of the wave dynamics in time domain are obtained. The tachyonic instability is found to always occur for any nonzero black hole spin and any scalar field mass as long as the coupling constant exceeds a critical value. The presence of the mass term suppresses or even quench the instability. The quantitative dependence of the onset of the tachyonic instability on the coupling constant, the scalar field mass and the black hole spin is given numerically.

scholarly journals Exact black hole solutions with nonlinear electrodynamic field

2020 ◽  
Vol 29 (05) ◽  
pp. 2050032
Author(s):  
Shuang Yu ◽  
Changjun Gao
Keyword(s):  
Black Hole ◽  
Cosmological Constant ◽  
Electric Charge ◽  
Single Phase ◽  
Causal Structure ◽  
Nonlinear Electrodynamic ◽  
Coupling Constant ◽  
De Sitter ◽  
Black Hole Solutions ◽  
Three Phases

We construct exact black hole solutions to Einstein gravity with nonlinear electrodynamic field. In these solutions, there are, in general, four parameters. They are physical mass, electric charge, cosmological constant and the coupling constant. These solutions differ significantly from the Reissner–Nordström–de Sitter solution in Einstein–Maxwell gravity with a cosmological constant, due to the presence of coupling constant. For example, some of them are endowed with a topological defect on angle [Formula: see text] and the electric charge of some can be much larger or smaller than their mass by varying the coupling constant. On the other hand, these spacetimes are all asymptotically de Sitter (or anti-de Sitter). As a result, their causal structure is similar to the Reissner–Nordström–de Sitter spacetime. Finally, the investigations on the thermodynamics reveal that the coupling constant except for solution-4 has the opposite effect as temperature on the phase, structure of black holes. Concretely, the phase-space changes from single phase to three phases with the decrease of temperature. On the contrary, it changes from three phases to a single phase with the decrease of coupling constant.

scholarly journals Solutions with throats in Hořava gravity with cosmological constant

2016 ◽  
Vol 25 (02) ◽  
pp. 1650016 ◽  
Author(s):  
Jorge Bellorín ◽  
Alvaro Restuccia ◽  
Adrián Sotomayor
Keyword(s):  
Cosmological Constant ◽  
Effective Action ◽  
Naked Singularity ◽  
Shift Function ◽  
Coupling Constant ◽  
De Sitter ◽  
Single Side ◽  
Horava Gravity ◽  
Two Sides ◽  
Lapse Function

By combining analytical and numerical methods, we find that the solutions of the complete Hořava theory with negative cosmological constant that satisfy the conditions of staticity, spherical symmetry and vanishing of the shift function are two kinds of geometry: (i) a solution with two sides joined by a throat and (ii) a single side with a naked singularity at the origin. We study the second-order effective action. We consider the case when the coupling constant of the [Formula: see text] term, which is the unique deviation from general relativity (GR) in the effective action, is small. At one side, the solution with the throat acquires a kind of deformed anti-de Sitter (AdS) asymptotia and at the other side, there is an asymptotic essential singularity. The deformation of AdS essentially means that the lapse function [Formula: see text] diverges asymptotically a bit faster than AdS. This can also be interpreted as an anisotropic Lifshitz scaling that the solutions acquire asymptotically.

scholarly journals LOCAL OBSERVED TIME AND REDSHIFT IN CURVED SPACE–TIME

2001 ◽  
Vol 16 (21) ◽  
pp. 1385-1393 ◽  
Author(s):  
SZE-SHIANG FENG
Keyword(s):  
Cosmological Constant ◽  
Time Scale ◽  
Space Time ◽  
Local Observable ◽  
Length Scale ◽  
De Sitter ◽  
Perfect Agreement ◽  
Curved Space ◽  
De Sitter Universe ◽  
Changing Rate

Using the observed time and spatial intervals defined originally by Einstein and the observational frame in the vierbein formalism, we propose that in curved space–time, for a wave received in laboratories, the observed frequency is the changing rate of the phase of the wave relative to the local observable time scale and the momentum is the changing rate of the phase relative to the local observable spatial length scale. The case of Robertson–Walker universe is especially considered and the application to de Sitter universe results in a cosmological constant in perfect agreement with the observational data.

scholarly journals TURBULENT INSTABILITY OF ANTI-DE SITTER SPACE–TIME

2013 ◽  
Vol 28 (22n23) ◽  
pp. 1340020 ◽  
Author(s):  
MACIEJ MALIBORSKI ◽  
ANDRZEJ ROSTWOROWSKI
Keyword(s):  
Scalar Field ◽  
Cosmological Constant ◽  
Numerical Study ◽  
De Sitter Space ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Spherically Symmetric ◽  
De Sitter ◽  
Field System ◽  
Technical Details

In these lecture notes, we discuss recently conjectured instability of anti-de Sitter space, resulting in gravitational collapse of a large class of arbitrarily small initial perturbations. We uncover the technical details used in the numerical study of spherically symmetric Einstein-massless scalar field system with negative cosmological constant that led to the conjectured instability.

scholarly journals Inhomogeneous compact extra dimensions and de Sitter cosmology

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Kirill A. Bronnikov ◽  
Arkady A. Popov ◽  
Sergey G. Rubin
Keyword(s):  
Scalar Field ◽  
Cosmological Constant ◽  
Field Distribution ◽  
Extra Dimensions ◽  
Factor Space ◽  
De Sitter ◽  
Extra Factor ◽  
De Sitter Metric

AbstractIn the framework of multidimensional f(R) gravity, we study the possible metrics of compact extra dimensions assuming that our 4D space has the de Sitter metric. Manifolds described by such metrics could be formed at the inflationary and even higher energy scales. It is shown that in the presence of a scalar field, it is possible to obtain a variety of inhomogeneous metrics in the extra factor space $${{\mathbb {M}}}_2$$ M 2 . Each of these metrics leads to a certain value of the 4D cosmological constant $$\varLambda _4$$ Λ 4 , and in particular, it is possible to obtain $$\varLambda _4 =0$$ Λ 4 = 0 , as is confirmed by numerically obtained solutions. A nontrivial scalar field distribution in the extra dimensions is an important feature of this family of metrics. The obtained solutions are shown to be stable under extra-dimensional perturbations.

scholarly journals PROBABILITY DISTRIBUTION FUNCTIONAL FOR EQUAL-TIME CORRELATION FUNCTIONS IN CURVED SPACE

1994 ◽  
Vol 09 (02) ◽  
pp. 221-238 ◽  
Author(s):  
HIROSHI SUZUKI ◽  
MISAO SASAKI ◽  
KAZUHIRO YAMAMOTO ◽  
JUN’ICHI YOKOYAMA
Keyword(s):  
Probability Distribution ◽  
Correlation Functions ◽  
Spatial Configuration ◽  
Scaling Law ◽  
Time Correlation ◽  
Ultraviolet Divergence ◽  
Coupling Constant ◽  
De Sitter ◽  
Curved Space ◽  
First Order

We present a systematic method to calculate the probability distribution functional (PDF) for spatial configuration of an interacting field in curved space-time. As an example, we consider PDF for the minimally coupled massive λΦ4 theory up to the first order of the coupling constant and evaluate it both in Minkowski and de Sitter spacetimes. We observe that PDF has an ultraviolet divergence even after the ultraviolet renormalization. This divergence is unavoidable to reproduce finite expectation values; thus some kind of regularization is necessary to write down PDF. As an application of it, a scaling law among multipoint correlation functions in the de Sitter space is found.

scholarly journals Evaluation of the Cosmological Constant in Inflation with a Massive Nonminimal Scalar Field

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Jung-Jeng Huang
Keyword(s):  
Scalar Field ◽  
Dispersion Relation ◽  
Energy Density ◽  
Cosmological Constant ◽  
Vacuum Energy ◽  
Vacuum State ◽  
Energy Scale ◽  
Quantum Evolution ◽  
Vacuum Energy Density ◽  
De Sitter

In Schrödinger picture we study the possible effects of trans-Planckian physics on the quantum evolution of massive nonminimally coupled scalar field in de Sitter space. For the nonlinear Corley-Jacobson type dispersion relations with quartic or sextic correction, we obtain the time evolution of the vacuum state wave functional during slow-roll inflation and calculate explicitly the corresponding expectation value of vacuum energy density. We find that the vacuum energy density is finite. For the usual dispersion parameter choice, the vacuum energy density for quartic correction to the dispersion relation is larger than for sextic correction, while for some other parameter choices, the vacuum energy density for quartic correction is smaller than for sextic correction. We also use the backreaction to constrain the magnitude of parameters in nonlinear dispersion relation and show how the cosmological constant depends on the parameters and the energy scale during the inflation at the grand unification phase transition.

scholarly journals SIMPLEST COSMOLOGICAL MODEL WITH THE SCALAR FIELD II.

1998 ◽  
Vol 07 (01) ◽  
pp. 129-138 ◽  
Author(s):  
A. YU. KAMENSHCHIK ◽  
I. M. KHALATNIKOV ◽  
A. V. TOPORENSKY
Keyword(s):  
Phase Space ◽  
Scalar Field ◽  
Cosmological Model ◽  
Qualitative Analysis ◽  
Cosmological Constant ◽  
Numerical Calculations ◽  
Inflaton Field ◽  
Model Combining ◽  
Friedmann Robertson Walker

Continuing the investigation of the simplest cosmological model with the massive real scalar noninteracting inflaton field minimally coupled to gravity, we study an influence of the cosmological constant on the behavior of trajectories in closed minisuperspace Friedmann–Robertson–Walker model. Combining numerical calculations with qualitative analysis both in configuration and phase space we present a convenient classification of trajectories.

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