Conference: Meeting of the National Research Group on Gravitational Waves

Session

Contributed talks: Cosmology

31 mars 2021, 14:00

70. Probing the inflationary particle content with gravitational waves

Matteo Fasiello (IFT UAM-CSIC, Madrid)

31/03/2021 14:00

COSMOLOGIE

I will highlight the immense discovery potential on early universe physics stemming from gravitational wave probes. To this aim, I will survey two approaches to inflation, from the particular (axion inflation models) to the general (an EFT approach).
I will show how a characterisation of the GW signal that includes (i) frequency profile, (ii) chirality, (iii) higher-point functions, (iv)...

56. Kination cosmology from scalar fields and gravitational-wave signatures

Peera Simakachorn (Universität Hamburg and DESY)

31/03/2021 14:15

COSMOLOGIE

A scalar field with large kinetic energy can dominate the Universe at early times and generates the so-called kination era. We present a natural and well-motivated particle physics realization, based simply on a Peccei-Quinn mechanism. The presence of kination imprints a smoking-gun spectral enhancement in the stochastic gravitational-wave (GW) background. Current and future-planned GW...

40. Gravitational radiation from MHD turbulence in the early universe

Alberto Roper Pol (APC)

31/03/2021 14:30

COSMOLOGIE

The generation of primordial magnetic fields and its interaction with the primordial plasma during cosmological phase transitions is turbulent in nature. I will describe and discuss results of direct numerical simulations of magnetohydrodynamic (MHD) turbulence in the early universe and the resulting stochastic gravitational wave background (SGWB). In addition to the SGWB, the primordial...

79. Theoretical uncertainties for cosmological phase transitions

Oliver Gould (University of Nottingham)

31/03/2021 14:45

COSMOLOGIE

A first-order phase transition in the early universe would have given rise to a stochastic gravitational wave background which may be observable today. Starting from a particle physics Lagrangian, the first step in making predictions of the gravitational wave signal is to understand the thermodynamics of the phase transition. In this talk, I will discuss the current situation regarding the...

61. Cosmology with dark gravitational wave sources

Suvodip Mukherjee (University of Amsterdam)

31/03/2021 15:00

COSMOLOGIE

Several observations using electromagnetic signal have led to a paradigm shift in our understanding of the Universe, with the realization that two unknown quantities - namely dark matter and dark energy - constitute about 95% of the Universe, even though their existence could not be explained by the known laws of physics and fundamental particles discovered until now. Moreover, measurements of...

81. Constraining the Hubble constant and modified GW propagation with LIGO/Virgo dark sirens and galaxy catalogs

Mancarella Michele (Université de Genève)

31/03/2021 15:15

COSMOLOGIE

I will present the methodology for constraining the Hubble parameter and modified GW propagation with “dark sirens” (namely, compact binary coalescences without an electromagnetic counterpart) and galaxy catalogs.
I will introduce in particular some relevant improvements to the treatment of the latter, such as their completeness, and discuss the correct treatment of selection bias. I will...

71. Mapping the inhomogeneous Universe with Standard Sirens: Degeneracy between inhomogeneity and modified gravity theories

Marios Kalomenopoulos (University of Edinburgh)

31/03/2021 15:30

COSMOLOGIE

The detection of gravitational waves (GWs) and an accompanying electromagnetic (E/M) counterpart have been suggested as a future probe for cosmology and theories of gravity. In this work, we present calculations of the luminosity distance of sources taking into account inhomogeneities in the matter distribution that are predicted in numerical simulations of structure formation. In addition, we...

41. Study of Neutron Star in the presence of Dark Matter

Harish Chandra Das (Institute of Physics, Bhubaneswar, Odisha, India)

31/03/2021 15:45

COSMOLOGIE

Neutron stars (NSs), being one of the most enigmatic stellar remnants with incredibly dense core and sturdy crust, can be considered as the best laboratory in the universe to appraise many astrophysical models of the strong gravitational field regime. We analyse the effects of dark matter on the properties and curvature of the NS with the help of relativistic mean-field (RMF) formalism using...