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Related papers: Holographic multiverse and conformal invariance

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We study Euclidean wineglass wormholes, which mediate the nucleation of inflationary spacetimes from an existing spacetime with asymptotically flat or Anti-de Sitter regions. These wormholes are distinguished by the presence of a local…

High Energy Physics - Theory · Physics 2026-05-12 George Lavrelashvili , Jean-Luc Lehners

In this paper, we consider a non-minimally coupled gravity model to study the bouncing universe. The holographic principle has various effects on the bouncing universe. We choose some suitable new variables and achieve the new Hamiltonian…

General Relativity and Quantum Cosmology · Physics 2023-04-28 Sudhaker Upadhyay

The separate-universe approach gives an intuitive way to understand the evolution of cosmological perturbations in the long-wavelength limit. It uses solutions of the spatially-homogeneous equations of motion to model the evolution of the…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-13 Joseph H. P. Jackson , Hooshyar Assadullahi , Andrew D. Gow , Kazuya Koyama , Vincent Vennin , David Wands

An effective theory based on wave optics is used to describe indeterminacy of position in holographic spacetime with a UV cutoff at the Planck scale. Wavefunctions describing spacetime positions are modeled as complex disturbances of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Craig J. Hogan

We propose a class of scalar models that, once coupled to gravity, lead to cosmologies that smoothly and stably connect an inflationary quasi-de Sitter universe to a low, or even zero-curvature, maximally symmetric spacetime in the…

High Energy Physics - Theory · Physics 2015-06-23 David Pirtskhalava , Luca Santoni , Enrico Trincherini , Patipan Uttayarat

We develop a new class of chaotic inflation models with spontaneously broken conformal invariance. Observational consequences of a broad class of such models are stable with respect to strong deformations of the scalar potential. This…

High Energy Physics - Theory · Physics 2015-06-16 Renata Kallosh , Andrei Linde

We consider the quasi-de Sitter geometry of the inflationary universe. We calculate the energy flux of the slowly rolling background scalar field through the quasi-de Sitter apparent horizon and set it equal to the change of the entropy…

High Energy Physics - Theory · Physics 2009-11-07 Andrei Frolov , Lev Kofman

A Multiverse can arise from landscapes without de Sitter minima. It can be populated during a period of eternal inflation without trans-Planckian field excursions and without flat potentials. This Multiverse can explain the values of the…

High Energy Physics - Phenomenology · Physics 2024-09-04 Raffaele Tito D'Agnolo , Paolo Mangini , Gabriele Rigo , Lian-Tao Wang

During inflation, the geometry of spacetime is described by a (quasi-)de Sitter phase. Inflationary observables are determined by the underlying (softly broken) de Sitter isometry group SO(1, 4) which acts like a conformal group on R^3:…

High Energy Physics - Theory · Physics 2016-01-20 Alex Kehagias , Antonio Riotto

The inflationary phase of the Universe is explored by proposing a toy model related to the scalar field, termed as {\it inflaton}. The potential part of the energy density in the said era is assumed to have a constant vacuum energy density…

General Physics · Physics 2019-05-22 Indranath Bhattacharyya , Saibal Ray , Prasenjit Paul

In this paper we find a solution for a quasi-isotropic inflationary Universe which allows to introduce in the problem a certain degree of inhomogeneity. We consider a model which generalize the (flat) FRW one by introducing a first order…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Giovanni Paolo Imponente , Giovanni Montani

In this work we investigate the behavior of three-dimensional (3D) cosmological models. The simulation of inflationary and dark-energy-dominated eras are among the possible results in these 3D formulations; taking as starting point the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 M. H. Christmann , F. P. Devecchi , G. M. Kremer , C. M. Zanetti

Starting with the Lagrangian formulation of General Relativity, we will conduct an investigation into the production of spacetime waves, due to a geometric boundary term of a closed extended manifold, within the tensor and scalar sectors.…

General Relativity and Quantum Cosmology · Physics 2023-07-24 Rafael Hernández-Jiménez , Claudia Moreno

In holographic models of cosmology based on the (A)dS/CFT correspondence, conformal symmetry is implicit in the dual description of the Universe. Generically, however, one cannot expect the (broken) conformal invariance in the cosmic…

High Energy Physics - Theory · Physics 2015-06-19 Shinsuke Kawai , Yu Nakayama

We present an inflationary universe model which utilizes two coupled real scalar fields. The inflation field $\phi$ experiences a first order phase transition and its potential dominates the energy density of the Universe during the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Fred C. Adams , Katherine Freese

Cosmological N-body simulations with scale-invariant initial perturbations show too many virialized objects of dwarf-galaxy masses in a typical galactic halo in contradiction to observation and stability of galactic discs. We present a…

Astrophysics · Physics 2008-11-26 Jun'ichi Yokoyama

The physics of the inflationary universe requires the study of the out of equilibrium evolution of quantum fields in curved spacetime. We present the evolution for both the geometry and the matter (described by the quantum inflaton field)…

Astrophysics · Physics 2007-05-23 D. Boyanovsky , D. Cormier , H. J. de Vega , R. Holman , S. P. Kumar

We investigate the quantum dynamics of the quasi-isotropic inflationary solution. This is achieved by deriving the Lagrangian and Hamiltonian for both the FLRW background and the inhomogeneous correction, via an expansion of the…

General Relativity and Quantum Cosmology · Physics 2022-12-19 Nicola Bortolotti , Giovanni Montani

Supersymmetric hybrid inflation is an exquisite framework to connect inflationary cosmology to particle physics at the scale of grand unification. Ending in a phase transition associated with spontaneous symmetry breaking, it can naturally…

High Energy Physics - Phenomenology · Physics 2014-07-31 Wilfried Buchmuller , Valerie Domcke , Kohei Kamada , Kai Schmitz

It is proposed that if quantum states of space-time are coherent on null surfaces, holographic Planck-scale fluctuations of inflationary horizons dominate the formation of primordial scalar curvature perturbations. It is shown that the…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-17 Craig Hogan