Results 21 to 30 of about 46,785 (128)
Inflation with a negative cosmological constant [PDF]
Physical Review D, 2009 We find a unique way of realizing inflation through cyclic phases in an universe with negative vacuum energy. According to the second law of thermodynamics entropy monotonically increases from cycle to cycle, typically by a constant factor. This means that the scale factor at the same energy density in consecutive cycles also increases by a constant ...
Anupam Mazumdar +2 more
openaire +4 more sources
Stringy Effects During Inflation and Reheating [PDF]
, 2005 We consider inflationary cosmology in the context of string compactifications with multiple throats. In scenarios where the warping differs significantly between throats, string and Kaluza-Klein physics can generate potentially observable corrections to ...
A. Vilenkin +6 more
core +3 more sources
Inflation and Cosmological Perturbations [PDF]
, 2010 56 pages, 5 figures; Lectures given at the Second TRR33 Winter School on cosmology, Passo del Tonale (Italy), December ...
openaire +6 more sources
Higgs Inflation and the Cosmological Constant [PDF]
Acta Physica Polonica B, 2014 The Higgs not only induces the masses of all SM particles, the Higgs, given its special mass value, is the natural candidate for the inflaton and in fact is ruling the evolution of the early universe, by providing the necessary dark energy which remains the dominant energy density.
openaire +5 more sources
D-term inflation in D-brane cosmology [PDF]
, 2005 We consider hybrid inflation in the braneworld scenario. In particular, we consider inflation in global supersymmetry with the D-terms in the scalar potential for the inflaton field to be the dominant ones (D-term inflation).
Altendorfer +35 more
core +2 more sources
Cosmological perturbations without inflation [PDF]
Classical and Quantum Gravity, 2016 A particularly attractive feature of inflation is that quantum fluctuations inthe inflaton field may have seeded inhomogeneities in the cosmic microwavebackground (CMB) and the formation of large-scale structure. In this paper,we demonstrate that a scalar field with zero active mass, i.e., with anequation of state $\rho+3p=0$, where $\rho$ and $p$ are ...
openaire +5 more sources
, 1995 An exploratory study of the cosmology of moduli in string theory. Moduli are argued to be natural inflaton fields and lead to a robust inflationary cosmology in which inflation takes place at the top of domain walls. The amplitude of microwave background
A. Albrecht +54 more
core +2 more sources
Towards a cosmological dual to inflation
Physical Review D, 2011 We derive all single-field cosmologies with unit sound speed that generate scale invariant curvature perturbations on a dynamical attractor background. We identify three distinct phases: slow-roll inflation; a slowly contracting adiabatic ekpyrotic phase, described by a rapidly-varying equation of state; and a novel adiabatic ekpyrotic phase on a ...
Khoury, Justin, Miller, Godfrey E.J.
openaire +5 more sources
Inflation and Alternatives with Blue Tensor Spectra
, 2014 We study the tilt of the primordial gravitational waves spectrum. A hint of blue tilt is shown from analyzing the BICEP2 and POLARBEAR data. Motivated by this, we explore the possibilities of blue tensor spectra from the very early universe cosmology ...
Wang, Yi, Xue, Wei
core +2 more sources
Back Reaction and Graceful Exit in String Inflationary Cosmology [PDF]
, 1996 Classical string cosmology consists of two branches related to each other by scale-factor duality: a super-inflation branch and a Friedmann-Robertson-Walker (FRW) branch. Curvature and string coupling singularity separates the two branches, hence posing `
A. Albrecht +21 more
core +2 more sources