I present a new framework—Asymgenesis—that connects the baryon asymmetry of the universe to the dark matter density within the standard type-I seesaw model. The mechanism starts from a primordial charge asymmetry, either in the visible or dark sector, and redistributes it via a higher-dimensional portal operator. This process generates both a nonzero $B-L$ asymmetry and an asymmetric dark...
In this talk, we explore the role of non-equilibrium dynamics within a thermal plasma in the context of processes in the early Universe and astrophysical environments. Our approach is based on one-particle-irreducible (1PI) resummed propagators computed within the real-time formalism of thermal field theory, allowing us to consistently include thermal masses, widths, and other non-trivial...
Strong Interacting Massive Particles are a well motivated DM candidate. In particular we took into consideration a QCD-like theory with three flavours, where the DM candidate is a dark pion. In Ref[2405.10367], it has been found that a non-vanishing theta angle would trigger resonant processes which would give rise to the observed relic density, together with providing velocity dependent...
We propose a novel realization of Dirac leptogenesis by sourcing the required lepton asymmetry via inflationary dynamics. In particular, an asymmetry is generated in the scalar sector of the model during the reheating phase and is then transferred to the leptonic sector via Yukawa interactions and subsequently to a baryon asymmetry via weak sphaleron processes. The current scenario also offers...
We study the possibility of generating matter-antimatter asymmetry in the early Universe before the Electroweak phase transition by considering three Dirac right-handed neutrinos in addition to the standard model particles using the CTP formalism. In addition, we consider two off-shell heavy scalars, so the temperature of the Universe is never required to be high enough after inflation to...
Ultralight particles, with a mass below the electronvolt scale, exhibit wave-like behavior and have arisen as a compelling dark matter candidate. A particularly intriguing subclass is scalar dark matter, which induces variations in fundamental physical constants. However, detecting such particles becomes highly challenging in the mass range above $10^{-6}\,\text{eV}$, as traditional...
Anisotropies play a central role in distinguishing between a cosmological or astrophysical origin of the nanohertz gravitational wave background, as detectable anisotropies are expected for a GWB from a population of supermassive black hole binaries but not for cosmological sources.
We analyze prospects for detecting anisotropies from either bright single sources or large scale anisotropies...
Blazars are a subclass of active galactic nuclei (AGN), the brightest continuously emitting sources in the Universe, powered by accreting supermassive black holes (SMBH). Their defining characteristic is the presence of powerful, back-to-back relativistic jets of protons and electrons, with one jet closely aligned in the direction of Earth. This offers a unique opportunity to probe physics...
In this talk, I will present a detailed study of the cosmological constraints on the decay of a relic particle into neutrinos, in particular those arising from the observed light-element abundances in the early Universe. I will focus on the late-time disintegration of the light elements previously synthesised during BBN. Several processes are relevant, including final-state radiation...
During a neutron star's formation in a supernova, its core may undergo a phase transition into deconfined quark matter. The phase transition would likely be first-order, proceeding by bubble nucleation. We show that such a phase transition would be accompanied by the emission of high-frequency gravitational waves (MHz band), which could be within reach of proposed gravitational wave detectors....
It has been demonstrated that axions can generically copiously produced from fluctuations in the background electromagnetic fields of pulsars. For axions with masses in the range $10^{-9} \text{eV} \lesssim m_a \lesssim 10^{-4} \text{eV}$, a large fraction of axions sourced from this process will remain gravitationally confined near the surface of the star, accumulating on long timescales,...
