Tada, Yuichiro Vennin, Vincent

We present a generic framework to compute the one-point statistics of cosmological perturbations, when coarse-grained at an arbitrary scale $R$, in the presence of quantum diffusion. Making use of the stochastic-$\delta N$ formalism, we show how it can be related to the statistics of the amount of expansion realised until the scale $R$ crosses out ...

Ng, Kin-Wang Wu, Yi-Peng
Published in
Journal of High Energy Physics

Constant-rate inflation, including ultra-slow-roll inflation as a special case, has been widely applied to the formation of primordial black holes with a significant deviation from the standard slow-roll conditions at both the growing and decaying phases of the power spectrum. We derive analytic solutions for the curvature perturbations with respec...

Chaudhuri, Arnab Khlopov, Maxim Yu.

When the vacuum like energy of the Higgs potential within the standard model undergoes electroweak phase transition, an influx of entropy into the primordial plasma can lead to a significant dilution of frozen out dark matter density that was already present before the onset of the phase transition. The same effect can take place, if the early Univ...

Khlopov, M. Yu.
Published in
Astronomy Reports

AbstractThe modern Standard cosmological scenario, reflecting to large extent the development of Zeldovich’s legacy in cosmoparticle physics, involves inflation, baryosynthesis and dark matter/energy. Physics of all these elements of the cosmological paradigm lays Beyond the Standard model (BSM) of elementary particles and involves in its turn cosm...

Musco, Ilia Papanikolaou, Theodoros

This work investigates the formation of primordial black holes within a radiation fluid with an anisotropic pressure. We focus our attention on the initial conditions describing cosmological perturbations on the super horizon regime, using a covariant form of the equation of state in terms of pressure and energy density gradients. The effect of the...

Martin, Jerome Vennin, Vincent

We compute the entanglement entropy, mutual information and quantum discord of the Cosmic Microwave Background (CMB) fluctuations in real space. To that end, we first show that measurements of these fluctuations at two distinct spatial locations can be described by a bipartite, continuous Gaussian system. This leads to explicit formulas for the mut...

Wu, Yi-Peng Pinetti, Elena Silk, Joseph

If primordial black holes (PBHs) contribute more than 10 percent of the dark matter (DM) density, their energy density today is of the same order as that of the baryons. Such a cosmic coincidence might hint at a mutual origin for the formation scenario of PBHs and the baryon asymmetry of the Universe. Baryogenesis can be triggered by a sharp transi...

Génolini, Yoann Boudaud, Mathieu Cirelli, Marco Derome, Laurent Lavalle, Julien Maurin, David Salati, Pierre Weinrich, Nathanael

Galactic charged cosmic rays (notably electrons, positrons, antiprotons and light antinuclei) are powerful probes of dark matter annihilation or decay, in particular for candidates heavier than a few MeV or tiny evaporating primordial black holes. Recent measurements by PAMELA, AMS-02, or VOYAGER on positrons and antiprotons already translate into ...

Kritos, Konstantinos Silk, Joseph

Near-extremal primordial black holes stable over cosmological timescales may constitute a significant fraction of the dark matter. Due to their charge the coalescence rate of such black holes is enhanced inside clusters and the non-extremal merger remnants are prone to Hawking evaporation. We demonstrate that if these clusters of near-extremal hole...

Siegert, Thomas Boehm, Celine Calore, Francesca Diehl, Roland Krause, Martin G.H. Serpico, Pasquale D. Vincent, Aaron C.

Reticulum II (Ret II) is a satellite galaxy of the Milky Way and presents a prime target to investigate the nature of dark matter (DM) because of its high mass-to-light ratio. We evaluate a dedicated INTEGRAL observation campaign data set to obtain $\gamma$-ray fluxes from Ret II and compare those with expectations from DM. Ret II is not detected i...