Concept

Ekpyrotic universe

Related publications (29)

Growth and investigation of Argon thin films adsorbed on graphite by means of Ultrafast Electron Diffraction

Starting from our big universe to the microscopic world, phase transitions play an important role in nature. Just after the Big Bang our universe experienced multiple phase transitions, from high-temperature plasma to the matter we know today. Phase transi ...

EPFL2023

Detectability of Large Correlation Length Inflationary Magnetic Field with Cherenkov Telescopes

Andrii Neronov

Magnetic fields occupying the voids of the large scale structure may be a relic from the Early Universe originating from either Inflation or from cosmological phase transitions. We explore the possibility of identifying the inflationary origin of the void ...

2022

Cosmology intertwined: A review of the particle physics, astrophysics, and cosmology associated with the cosmological tensions and anomalies

Frédéric Courbin, Julien Lesgourgues, Mikhail Ivanov, Richard Irving Anderson

The standard Lambda Cold Dark Matter (Lambda CDM) cosmological model provides a good description of a wide range of astrophysical and cosmological data. However, there are a few big open questions that make the standard model look like an approximation to ...

ELSEVIER2022

Constraining dark photons and their connection to 21 cm cosmology with CMB data

Kyrylo Bondarenko

In the inhomogeneous Universe, the cosmological conversion of dark photons into ordinary photons (and vice versa) may happen at a great number of resonance redshifts. This alters the CMB observed energy spectrum and degree of small-scale anisotropies. We u ...

2020

Quantum effects in Palatini Higgs inflation

Mikhail Chapochnikov, Andrey Shkerin, Sebastian Zell

We study quantum effects in Higgs inflation in the Palatini formulation of gravity, in which the metric and connection are treated as independent variables. We exploit the fact that the cutoff, above which perturbation theory breaks down, is higher than th ...

IOP PUBLISHING LTD2020

Advanced gravitational lensing techniques for precision cosmology

Markus Rexroth

Gravitational lensing - the deflection of light by gravity - has greatly developed since its famous first observation in 1919, which validated Einstein's General Theory of Relativity. The strength of this effect does not depend on the nature of the mass wh ...

EPFL2018

Emergence of Friedmann Equation of Cosmology of a Flat Universe from the Time-Energy Uncertainty Principle

Farhad Rachidi-Haeri

Friedmann equation of cosmology is based on the field equations of general relativity. Its derivation is straight-forward once the Einstein’s field equations are given and the derivation is independent of quantum mechanics. In this paper, it is shown that ...

2017

On the dark radiation problem in the axiverse

Anna Tokareva

String scenarios generically predict that we live in a so called axiverse: the Universe with about a hundred of light axion species which are decoupled from the Standard Model particles. However, the axions can couple to the inflaton which leads to their p ...

Iop Publishing Ltd2017

Initial condition for baryogenesis via neutrino oscillation

Shintaro Eijima

We consider a baryogenesis scenario via the oscillation of right-handed neutrinos with Majorana masses of the order of GeV, which are also responsible for neutrino masses by the seesaw mechanism. We study how the initial condition alters the prediction of ...

American Physical Society2017

Asymmetric dark matter and baryogenesis from pseudoscalar inflation

Eray Sabancilar

We show that both the baryon asymmetry of the Universe and the dark matter abundance can be explained within a single framework that makes use of maximally helical hypermagnetic fields produced during pseudoscalar inflation and the chiral anomaly in the St ...

Iop Publishing Ltd2017

SPIDERS: the spectroscopic follow-up of X-ray-selected clusters of galaxies in SDSS-IV

Jean-Paul Richard Kneib

SPIDERS (The SPectroscopic IDentification of eROSITA Sources) is a programme dedicated to the homogeneous and complete spectroscopic follow-up of X-ray active galactic nuclei and galaxy clusters over a large area (similar to 7500 deg(2)) of the extragalact ...

Oxford Univ Press2016

On the geometrical interpretation of scale-invariant models of inflation

Georgios Karananas, Javier Rubio

We study the geometrical properties of scale-invariant two-field models of inflation. In particular, we show that when the field-derivative space in the Einstein frame is maximally symmetric during inflation, the inflationary predictions can be universal a ...

Elsevier2016

Planck 2013 results. XXXII. The updated Planck catalogue of Sunyaev-Zeldovich sources

Xin Chen, Julien Lesgourgues

We update the all-sky Planck catalogue of 1227 clusters and cluster candidates (PSZ1) published in March 2013, derived from detections of the Sunyaev-Zeldovich (SZ) effect using the first 15.5 months of Planck satellite observations. As an addendum, we del ...

Edp Sciences S A2015

Inflation, LHC and the Higgs boson

Mikhail Chapochnikov

After the Higgs boson has been discovered, the Standard Model of particle physics became a confirmed theory, potentially valid up to the Planck scale and allowing to trace the evolution of the Universe from inflationary stage till the present days. We disc ...

World Scientific Publ Co Pte Ltd2015

Inflation, LHC and the Higgs boson

Mikhail Chapochnikov

After the Higgs boson has been discovered, the Standard Model of particle physics became a confirmed theory, potentially valid up to the Planck scale and allowing one to trace the evolution of the Universe from the inflationary stage till the present days. ...

Elsevier2015

Living beyond the edge: Higgs inflation and vacuum metastability

Mikhail Chapochnikov, Javier Rubio

The measurements of the Higgs mass and top Yukawa coupling indicate that we live in a very special universe, at the edge of the absolute stability of the electroweak vacuum. If fully stable, the Standard Model (SM) can be extended all the way up to the inf ...

American Physical Society2015

On the strong coupling scale in Higgs G-inflation

Higgs G-inflation is an inflation model that takes advantage of a Galileon-like derivative coupling. It is a non-renormalizable operator and is strongly coupled at high energy scales. Perturbative analysis does not have a predictive power any longer there. ...

Elsevier2015

Cosmological implications of baryon acoustic oscillation measurements

Jean-Paul Richard Kneib, David Schlegel, Timothée Guy Olivier Delubac

We derive constraints on cosmological parameters and tests of dark energy models from the combination of baryon acoustic oscillation (BAO) measurements with cosmic microwave background (CMB) data and a recent reanalysis of Type Ia supernova (SN) data. In p ...

American Physical Society2015

Constraints on primordial non-Gaussianity

Julien Lesgourgues

The Planck nominal mission cosmic microwave background (CMB) maps yield unprecedented constraints on primordial non-Gaussianity (NG). Using three optimal bispectrum estimators, separable template-fitting (KSW), binned, and modal, we obtain consistent value ...

Edp Sciences S A2014

Cosmology From Gravitational Lens Time Delays And Planck Data

Frédéric Courbin, Georges Meylan, Malte Tewes

Under the assumption of a flat Lambda CDM cosmology, recent data from the Planck satellite point toward a Hubble constant that is in tension with that measured by gravitational lens time delays and by the local distance ladder. Prosaically, this difference ...

Iop Publishing Ltd2014