Guiot, B. Borquez, A. Deur, A. Werner, K.
Published in
Journal of High Energy Physics

We investigate the possible existence of graviballs, a system of bound gravitons, and show that two gravitons can be bound together by their gravitational interaction. This idea connects to black hole formation by a high-energy 2 → N scattering and to the gravitational geon studied by Brill and Hartle. Our calculations rely on the formalism and tec...

Gannouji, Radouane Perivolaropoulos, Leandros Polarski, David Skara, Foteini

We consider Horndeski modified gravity models obeying stability, velocity of gravitational waves $c_T$ equals $c$ and quasistatic approximation (QSA) on subhorizon scales. We assume further a $\Lambda$CDM background expansion and a monotonic evolution on the cosmic background of the $\alpha$ functions as $\alpha_i= \alpha_{i0}~a^s$ where $i=M,B$, $...

Michaux, Michaël Hahn, Oliver Rampf, Cornelius Angulo, Raul E.

Inaccuracies in the initial conditions for cosmological N-body simulations could easily be the largest source of systematic error in predicting the non-linear large-scale structure. From the theory side, initial conditions are usually provided by using low-order truncations of the displacement field from Lagrangian perturbation theory, with the fir...

Savalle, Etienne

Cette thèse présente deux projets de recherche qui se placent dans le contexte des deux grandes théories de la physiquemoderne : la relativité générale et le modèle standard.— Le premier projet a pour objectif de mesurer le décalage vers le rouge gravitationnel entre l’horloge PHARAOde l’ensemble ACES-PHARAO (qui sera arrimé à l’ISS) et les meilleu...

de Anda, Francisco J. Antoniadis, Ignatios Valle, José W. F. Vaquera-Araujo, Carlos A.
Published in
Journal of High Energy Physics

We propose a flavour theory in which the family symmetry results naturally from a six-dimensional orbifold compactification. “Diracness” of neutrinos is a consequence of the spacetime dimensionality, and the fact that right-handed neutrinos live in the bulk. Dark matter is incorporated in a scotogenic way, as a result of an auxiliary ℤ3 symmetry, a...

Auclair, Pierre Peter, Patrick Ringeval, Christophe Steer, Danièle

The existence of a scaling network of current-carrying cosmic strings in our Universe is expected to continuously create loops endowed with a conserved current during the cosmological expansion. These loops radiate gravitational waves and may stabilise into centrifugally supported configurations. We show that this process generates an irreducible p...

Kuruvilla, Joseph Aghanim, Nabila McCarthy, Ian G.

We explore the impact of baryonic effects (namely stellar and AGN feedback) on the moments of pairwise velocity using the Illustris-TNG, EAGLE, cosmo-OWLS, and BAHAMAS suites of cosmological hydrodynamical simulations. The assumption that the mean pairwise velocity of the gas component follows that of the dark matter is studied here at small separa...

Beylin, V. Khlopov, M. Kuksa, V. Volchanskiy, N.

The history of dark universe physics can be traced from processes in the very early universe to the modern dominance of dark matter and energy. Here, we review the possible nontrivial role of strong interactions in cosmological effects of new physics. In the case of ordinary QCD interaction, the existence of new stable colored particles such as new...

Brunswic, Léo Buchert, Thomas

The standard model of cosmology with postulated dark energy and dark matter sources may be considered as a fairly successful fitting model to observational data. However, this model leaves the question of the physical origin of these dark components open. Fully relativistic contributions that act like dark energy on large scales and like dark matte...

Cacciapaglia, Giacomo Rosenlyst, Martin

We present a composite scotogenic model for neutrino masses, which are generated via loops of $\mathbb{Z}_2$-odd composite scalars. We considered three different approaches to the couplings of the neutrinos (including three right-handed singlets) and the composite sector: ETC-like four-fermion interactions, fundamental partial compositeness and fer...