Galaxy mergers are a standard aspect of galaxy formation and evolution, and most (likely all) large galaxies contain supermassive black holes. As part of the merging process, the supermassive black holes should in-spiral together and eventually merge, generating a background of gravitational radiation in the nanohertz to microhertz regime. An array of precisely timed pulsars spread across the...
An invitation to Win 2023 in Guangzhou, China.
The ANTARES underwater neutrino telescope, located in the Mediterranean Sea off the coast
of Toulon (France), has been continuously taking data since 2007 with the primary aim to detect astrophysical neutrinos in the TeV–PeV range. The optical properties of the deep-sea water allow for a large effective area and good pointing accuracy in all neutrino flavor channels, leading to an...
We propose a paradigm where the (QCD) axion’s unexplored cosmological evolution, a rotation in the field space, gives rise to the dark matter abundance, the observed baryon asymmetry of the Universe, and/or gravitational waves. The rotation is initiated by explicit Peccei-Quinn symmetry breaking effective in the early Universe. The abundance of axion dark matter is determined by the rotational...
Neutrinos play an important role in dense astrophysical environments, in particular core-collapse supernovae and binary compact merger remnants. Novel flavor mechanisms emerge in these environments due to matter, neutrino self-interactions and also shock waves and turbulence during supernova explosions. In this talk I will highlight recent progress in the field and I will discuss the upcoming...
If neutrino self-interactions arise from beyond-Standard Model physics, there will be scattering between astrophysical and cosmic background neutrinos. As a result, resonance features can appear in astrophysical neutrino spectra. While the flavor-diagonal case has been studied before numerically, we present an analytic result for arbitrary self-coupling matrix, allowing for possibilities such...
Self-interaction among the neutrinos in the early Universe has been proposed as a solution to the Hubble tension, a discrepancy between the measured values of the Hubble constant from CMB and low-redshift data. However, flavor-universal neutrino self-interaction is highly constrained by BBN and several laboratory experiments such as, tau and K-meson decay, double-neutrino beta decay etc. In...
Primordial black holes from the early Universe constitute an attractive non-particle dark matter candidate. I will discuss their intimate connection with astronomical puzzles like the origin of heavy elements (gold), ongoing boom in gravity wave and multi-messenger astronomy as well as novel ways how to search for them. Primordial black holes from the general formation scenario of bubble...