Workshop: Stochastic Background of Gravitational Waves

Thursday 14 Nov 2019, 10:00 → 16:30 Europe/Brussels

G/1-G.1.03 - J. Sacton (Building G)

The discovery of gravitational waves in 2016 has opened a new era in the exploration of our Universe. At present, several transient gravitational wave signals associated to binary system mergers have been reported by LIGO/VIRGO. An interesting open question is if the Universe is also permeated by a stochastic gravitational wave background, that can be of astrophysical or cosmological origin.

The aim of this workshop is to bring together experts on stochastic gravitational wave physics to discuss about the most recent updates and their interpretations in new physics models. The workshop will be informal with large time dedicated to questions and discussions.  

List of speakers:
Tania Regimbau (LAPP Annecy)
Iason Baldes (ULB)
Thomas Konstandin (DESY)
Jose Miguel No (Madrid University)

Please register timely to the event.
The workshop will take place at the Vrije Universiteit Brussel (Pleinlaan 2, 1050 Brussels) in the Jean Sacton seminar room at the IIHE (1G003)
 

The workshop is part of a series of Belgian GW meetings whose purpose is to encourage Belgian research on Gravitational Wave Physics.

The workshop is supported by the Strategic Research Program HEP@VUB.
The workshop is part of a series HEP@VUB Crosstalk Workshops whose objective is to promote interdisciplinary activities across research groups in theoretical and experimental aspects of particle physics, astro-particle physics and high-energy astrophysics

Local Organizers: Alberto Mariotti
For any additional information please contact Alberto Mariotti

10:00 Welcome

1 Tania Regimbau: "The quest for the Gravitational-Wave Stochastic Background with Advanced LIGO and Advanced Virgo"

A primary target for gravitational wave astronomy is the detection of a stochastic background formed by the superposition of many unresolved independent sources at different stages of the evolution of the Universe.
The recent observations of the merger of two black holes and also two neutron stars imply that the contribution of unresolved binary mergers up to a redshift of 20 may be detectable by Advanced LIGO and Advanced Virgo in the coming years
In this talk, I will give an overview of the different sources creating the stochastic gravitational-wave background, in particular the background from compact binary mergers, and I will introduce the data analysis methods used in the LIGO/Virgo collaboration to measure it. I will then present upper limits obtained by Advanced LIGO and Advanced Virgo in the most recent observing runs. I will also discuss how the future generation of detectors can be used to remove the astrophysical contribution in order to observe the signal of cosmological origin.

regimbau.pdf

2 Thomas Konstandin: "Electroweak baryogenesis"

Electroweak baryogenesis is a mechanism that aims at explaining the baryon asymmetry of the Universe. One of the essential ingredients is a strong first-order cosmological phase transition which at the same time produces gravitational waves. I will present the current status of electroweak baryogenesis in terms of low-energy and collider probes and how it relates to potential GW signals from the electroweak phase transition.

seminar.pdf

12:30 Lunch

3 Jose Miguel No: "Gravitational Waves from the Electroweak Phase Transition"

VUB_GW_JMNo_Final_Version.pdf

4 Iason Baldes: "Connection to Dark Matter"

LISA will test scenarios of strongly supercooled phase transitions at the TeV scale by searching for a stochastic background of gravitational waves. I will discuss how such a phase transition can be closely tied to the relic abundance of dark matter in certain classes of models which feature close-to-conformal potentials. In confining phase transitions, for example, the yield of composite dark matter can be set in a process of hadronization as fundamental constituents enter the expanding bubbles. The gravitational wave signal from the phase transition gives a unique signature of such DM scenarios, complementary to collider, direct and indirect searches.

VUB_Baldes_nopause.pdf