4th EuCAPT Annual Symposium

Session

Early Universe

15 May 2024, 09:30

500/1-001 - Main Auditorium (CERN)

Conveners

Early Universe

• Mar Bastero Gil (University of Granada)

Early Universe

• Mar Bastero Gil (University of Granada)

136. Baryogenesis & Leptogenesis

Juraj Klaric (Universiteit van Amsterdam, Nikhef)

15/05/2024, 09:30

early universe cosmology

143. Cold-atom analogues of vacuum decay

Dr Alexander Jenkins (University College London)

15/05/2024, 10:00

138. Particle creation dynamics during inflation and reheating

Mathias Pierre

15/05/2024, 11:15

41. One-loop power spectrum in ultra slow-roll inflation and implications for primordial black hole dark matter

Jesus Gambin Egea (Instituto de Fisica Teorica, UAM - CSIC)

15/05/2024, 11:47

early universe cosmology

A possible way to generate primordial black holes as candidates for the entirety of dark matter is a large power spectrum of inflationary curvature fluctuations. Recently, questions have been raised regarding the validity of perturbation theory in this context. We compute the one-loop power spectrum in ultra-slow roll inflation, including all relevant interactions for such analysis, along with...

5. Backreaction of axion-SU(2) dynamics during inflation

Oksana Iarygina (Nordita)

15/05/2024, 11:54

early universe cosmology

Nowadays, the search for primordial gravitational waves is mainly focused on the parity-odd polarization pattern in the CMB - the B-modes. A correct interpretation of B-mode measurements strongly relies on understanding their production mechanism. One intriguing scenario is gravitational waves generation by gauge fields. The tachyonic amplification of the gauge fields modes during inflation...

62. Scale-invariant inflation

Chiara Cecchini (University of Trento, TIFPA-INFN)

15/05/2024, 12:01

early universe cosmology

Fundamental scale invariance has been proposed as a new theoretical principle beyond renormalizability. Besides its highly predictive power, a scale-invariant formulation of gravity could provide a natural explanation for the long-standing hierarchy problem and interesting applications in cosmology.
We present a globally scale-invariant model of quadratic gravity and study its solutions in a...

57. Black holes and gravitational waves from slow phase transitions

Piotr Toczek (University of Warsaw)

15/05/2024, 12:08

early universe cosmology

Slow first-order phase transitions generate large inhomogeneities that can lead to the formation of primordial black holes (PBHs). We show that the gravitational wave (GW) spectrum then consists of a primary component sourced by bubble collisions and a secondary one induced by large perturbations. The latter gives the dominant peak if $\beta/H_0 < 10$, impacting, in particular, the...

45. Hot Leptogenesis: A naturalness-motivated solution to baryon asymmetry

Ansh Bhatnagar (IPPP, Durham University)

15/05/2024, 12:15

early universe cosmology

In standard leptogenesis models, the baryon asymmetry is initially produced as a lepton asymmetry via the out of equilibrium decays of the lightest right handed neutrino (RHN).

There are however constraints on the RHN mass that are in tension; the naturalness constraint on the Higgs mass from RHN loop corrections, i.e. the Vissani bound, puts a limit on the RHN mass which is lower than is...

87. CMB spectral distortions from dark sector anisotropies

Nicklas Ramberg (Johannes gutenberg universität Mainz)

15/05/2024, 12:22

early universe cosmology

We introduce a novel approach to investigate sectors solely gravitationally coupled, characterized by significant anisotropies. These anisotropies undergo damping through gravitational interactions with the baryon-photon fluid, inducing heating in the process. The resultant injected heat leads to observable distortions in the cosmic microwave background spectrum. We provide analytic estimates...