Lee-Wick radiation induced bouncing universe models

Bhattacharya, Kaushik; Cai, Yi-Fu; Das, Suratna

doi:10.1103/physrevd.87.083511

Cited by 24 publications

(16 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To make this cancellation explicit in the LWSM, consider For the case σ = −1, we find that the free energy density is positive, which implies that the pressure, energy density, and entropy densities are negative. This result has been obtained previously in the context of toy LW theories [4,11], and its interesting implications have been studied in the context of early universe cosmology [37,38].…”

Section: Finite-temperature Behaviorsupporting

confidence: 75%

Lee-Wick standard model at finite temperature

2013

View full text Add to dashboard Cite

The Lee-Wick Standard Model at temperatures near the electroweak scale is considered, with the aim of studying the electroweak phase transition. While Lee-Wick theories possess states of negative norm, they are not pathological but instead are treated by imposing particular boundary conditions and using particular integration contours in the calculation of S-matrix elements. It is not immediately clear how to extend this prescription to formulate the theory at finite temperature; we explore two different pictures of finite-temperature LW theories, and calculate the thermodynamic variables and the (one-loop) thermal effective potential. We apply these results to study the LeeWick Standard Model and find that the electroweak phase transition is a continuous crossover, much like in the Standard Model. However, the high-temperature behavior is modified due to cancellations between thermal corrections arising from the negative-and positive-norm states.

show abstract

Section: Finite-temperature Behaviorsupporting

confidence: 75%

Lee-Wick standard model at finite temperature

2013

View full text Add to dashboard Cite

show abstract

“…Non-singular bouncing cosmologies can resolve the initial singularity problem of the inflationary ΛCDM model and hence have attracted a lot of attention in the literature. They appear in many theoretical settings where either the gravitational sector is modified as in Hoȓava gravity [56][57][58], non-relativistic gravitational action [59], torsion gravity [60,61], Lagrange-multiplier gravity [62,63], nonlinear massive gravity [64] and non-local gravity [65], or by making use of matter fields with the NEC violation such as in the quintom bounce [24,66], the Lee-Wick bounce [67,68], the ghost condensate bounce [69][70][71], and the S-brane bounce [72] models. A non-singular bounce may also be achieved in a universe with non-flat spatial geometry (see e.g.…”

Section: Toward the Big Bang In Bouncing Cosmology: The Paradigmmentioning

confidence: 99%

Exploring bouncing cosmologies with cosmological surveys

Cai

2014

Sci. China Phys. Mech. Astron.

Self Cite

204

169

View full text Add to dashboard Cite

In light of the recent observational data coming from the sky we have two significant directions in the field of theoretical cosmology recently. First, we are now able to make use of present observations, such as the Planck and BICEP2 data, to examine theoretical predictions from the standard inflationary ΛCDM which were made decades of years ago. Second, we can search for new cosmological signatures as a way to explore physics beyond the standard cosmic paradigm. In particular, a subset of early universe models admit a nonsingular bouncing solution that attempts to address the issue of the big bang singularity. These models have achieved a series of considerable developments in recent years, in particular in their perturbative frameworks, which made brand-new predictions of cosmological signatures that could be visible in current and forthcoming observations. In this article we present two representative paradigms of very early universe physics. The first is the so-called new matter (or matter-ekpyrotic) bounce scenario in which the universe starts with a matter-dominated contraction phase and transitions into an ekpyrotic phase. In the setting of this paradigm, we propose some possible mechanisms of generating a red tilt for primordial curvature perturbations and confront its general predictions with recent cosmological observations. The second is the matter-bounce inflation scenario which can be viewed as an extension of inflationary cosmology with a matter contraction before inflation. We present a class of possible model constructions and review its implications on the current CMB experiments. Last, we review the significant achievements of these paradigms beyond the inflationary ΛCDM model, which we expect to shed new light on the direction of observational cosmology in the next decade years.

show abstract

“…N=1 supergravity is used in a bounce model to eliminate ghost excitations [19] and to prove that nonsingular bounces were viable in supergravity. "G-Bounce" models generate a non-singularity inflation cosmos with a Galileon field [20], while Lee-Wick bounce produces a bounce in the radiation phase with an apparent scale invariance in the perturbation spectrum [21,22]. A bounce solution is also found in the universe dominated by the Quintom matter [23,24].…”

Section: Introductionmentioning

confidence: 99%

The CST bounce universe model — A parametric study

Cheung

Song

et al. 2018

Sci. China Phys. Mech. Astron.

View full text Add to dashboard Cite

A bounce universe model with a scale-invariant and stable spectrum of primordial density perturbations was constructed using a consistent truncation of the D-brane dynamics from Type IIB string theory. A coupling was introduced between the tachyon field and the adjoint Higgs field on the D3-branes to lock the tachyon at the top of its potential hill and to model the bounce process, which is known as the Coupled Scalar and Tachyon Bounce (CSTB) Universe. The CSTB model has been shown to be ghost free, and it fulfils the null energy condition; in addition, it can also solve the Big Bang cosmic singularity problem. In this paper we conduct an extensive follow-up study of the parameter space of the CSTB model. In particular we are interested in the parameter values that can produce a single bounce to arrive at a radiation-dominated universe. We further establish that the CSTB universe is a viable alternative to inflation, as it can naturally produce a sufficient number of e-foldings in the locked inflation epoch and in the post-bounce expansion to overcome the four fundamental limitations of the Big Bang cosmology, which are flatness, horizon, homogeneity and singularity, resulting in a universe of the current size.bounce universe, big bang singularity, tachyon inflation, flatness and horizon problems PACS number(s): 11.25. Uv, 11.25.Mj, 11.25.Wx, 98.80.k, 98.80.Cq

show abstract

Lee-Wick radiation induced bouncing universe models

Cited by 24 publications

References 55 publications

Lee-Wick standard model at finite temperature

Lee-Wick standard model at finite temperature

Exploring bouncing cosmologies with cosmological surveys

The CST bounce universe model — A parametric study

Contact Info

Product

Resources

About