Jeans’ instability analysis of scalar field halos

We construct an inflation model on the Randall–Sundrum I (RSI) brane where a bulk scalar field stabilizes the inter-brane separation. We study impact of the bulk scalar field on the inflationary dynamics on the brane. We proceed in two different approaches: in the first approach, the stabilizing field potential is directly appeared in the Friedmann equation and the resulting scenario is effectively a two-field inflation. In the second approach, the stabilization mechanism is considered in the context of a warp factor so that there is just one field present that plays the roles of both inflaton and stabilizer. We study constraints imposed on the model parameters from recent observations.

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CASIMIR EFFECT FOR THE ROBIN SURFACES IN STATIC ROBERTSON–WALKER SPACE–TIME

International Journal of Modern Physics D ◽

10.1142/s0218271811018767 ◽

2011 ◽

Vol 20 (02) ◽

pp. 161-168 ◽

Cited By ~ 1

Author(s):

MOHAMMAD R. SETARE ◽

M. DEHGHANI

Keyword(s):

Scalar Field ◽

Energy Momentum Tensor ◽

Casimir Effect ◽

Vacuum Expectation ◽

Robin Boundary Condition ◽

Momentum Tensor ◽

Space Time ◽

Conformally Invariant ◽

Time Space ◽

Robin Boundary

We investigate the energy–momentum tensor for a massless conformally coupled scalar field in the region between two curved surfaces in k = -1 static Robertson–Walker space–time. We assume that the scalar field satisfies the Robin boundary condition on the surfaces. Robertson–Walker space–time space is conformally related to Rindler space; as a result we can obtain vacuum expectation values of the energy–momentum tensor for a conformally invariant field in Robertson–Walker space–time space from the corresponding Rindler counterpart by the conformal transformation.

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Effective masses in a dense fermion background — Applied to neutrinos, dark matter and dark energy

International Journal of Modern Physics A ◽

10.1142/s0217751x14440102 ◽

2014 ◽

Vol 29 (21) ◽

pp. 1444010

Author(s):

Bruce H. J. McKellar ◽

T. J. Goldman ◽

G. J. Stephenson

Keyword(s):

Dark Matter ◽

Dark Energy ◽

Scalar Field ◽

Effective Mass ◽

Negative Pressure ◽

Expectation Value ◽

Effective Masses ◽

Neutrino Astrophysics

If fermions interact with a scalar field, and there are many fermions present the scalar field may develop an expectation value and generate an effective mass for the fermions. This can lead to the formation of fermion clusters, which could be relevant for neutrino astrophysics and for dark matter astrophysics. Because this system may exhibit negative pressure, it also leads to a model of dark energy.

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ANTI-SELF-DUAL SOLUTIONS OF THE YANG-MILLS EQUATIONS IN 4n DIMENSIONS

Modern Physics Letters A ◽

10.1142/s0217732392001816 ◽

1992 ◽

Vol 07 (23) ◽

pp. 2077-2085 ◽

Cited By ~ 17

Author(s):

A. D. POPOV

Keyword(s):

Scalar Field ◽

Euclidean Space ◽

Lie Algebra ◽

Linear Equations ◽

Dual Solutions ◽

Gauge Fields ◽

System Of Equations ◽

Semisimple Lie Algebra ◽

Yang Mills ◽

Self Duality

The anti-self-duality equations for gauge fields in d = 4 and a generalization of these equations to dimension d = 4n are considered. For gauge fields with values in an arbitrary semisimple Lie algebra [Formula: see text] we introduce the ansatz which reduces the anti-self-duality equations in the Euclidean space ℝ4n to a system of equations breaking up into the well known Nahm's equations and some linear equations for scalar field φ.

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