We present an updated cosmological analysis of axion–lepton interactions, combining recent Planck CMB measurements with Baryon Acoustic Oscillation data from DESI DR2. Our approach incorporates non-thermal axion momentum distributions obtained by solving the full phase-space Boltzmann equation, allowing for a precise determination of axion abundance and energy density. We show that the...
For my master thesis, I will explore a procedure outlined in recent research for obtaining a stochastic GW spectrum from inflaton decay. The inflaton decays in two-body decay (inflaton to two RH neutrinos) and three-body decay (inflaton to two RH neutrinos + graviton). The gravitons produced in the inflaton are then interpreted classically as GWs. The criterion for non-thermal leptogenesis...
Although the current consensus ΛCDM model of the Universe successfully explains a wide range of observations, it continues to face persistent tensions, such as the Hubble tension, evidence for time-evolving dark energy (e.g., DESI results), and other anomalous findings. In this talk, I will present a concise review of cosmic voids, the largest observable structures in the Universe, and their...
This PhD project investigates strong-field gravity through optical signatures—such as black hole shadows and photon rings—produced by compact objects with accretion disks. These features encode spacetime geometry and offer observational means to identify deviations from General Relativity (GR). The research investigates both classical black holes and horizonless exotic objects arising in...
As one of the most prevailing frameworks for the earliest stages of the universe, Inflation efficiently addresses some of the long-standing cosmological puzzles, such as the horizon and flatness problems. It provides a compelling mechanism for the origin of primordial perturbations, linking gravitational dynamics to observable cosmological markers. Examined here in the Einstein-Cartan...
This study examines how inflationary dynamics are affected by $f(R)$-theories with a non-minimal coupling between matter and curvature. Both positive and negative corrections to the minimal coupling of General Relativity are considered, and a robust numerical method is developed that evolves the metric and the inflaton field in this modified theory beyond slow-roll. Through a stability...
Complementary to modified theories of gravity, disformal transformations provide a useful bridge onto particle physics. Examining their action on Dirac spinors offers a compelling intersection between cosmology, effective field theory, dark matter, and apparent Lorentz violations.
QCD-like theories are of interest in various areas of beyond-Standard-Model phenomenology, including composite Higgs models and strongly interacting pionic dark matter. The low-energy effective field theories provide a framework for describing the dynamics of such strongly coupled gauge theories.
In this work, we present next-to-leading order (NLO) expressions for masses, condensates, decay...
The so-called "strongly interacting massive particles" (SIMPs) refer to a class of dark matter candidates with the relic abundance set by the 3-to-2 interactions which allows for dark matter with sub-GeV masses, not yet strongly constrained by direct detection experiments. Interestingly, SIMP dark matter features relatively strong self-interactions that may explain the small-scale structure...
The project aims to investigate the origins of high-energy (HE) neutrinos and the role of tidally disrupted events (TDEs) as potential candidates for HE neutrino sources. It focuses on studying multi-wavelength correlations and estimating the neutrino energies. TDEs are unique transient phenomena that occur when a main-sequence star is torn apart by the gravitational pull of a nearby massive...
Dark photons are hypothetical particles that could connect the visible universe with a hidden dark sector. In this presentation, I propose a novel search strategy using the Brazilian Synchrotron Light Laboratory (LNLS). The idea is to produce dark photons via Inverse Compton scattering between laser photons and the 3 GeV electron beam at the LNLS. Using photon counting techniques, we estimate...
Non-minimal coupling between dark matter and gravity introduce a theoretically motivated extension to the standard ΛCDM framework, preserving its successful large-scale behavior while allowing scale-dependent deviations in the gravitational potential of bound structures. In this talk, I present observational constraints on a non-minimal coupling scenario, parameterized by a coupling scale L,...
Preheating refers to a well-known set of phenomena, such as tachyonic instability and parametric resonance, associated with the dynamics of a scalar field, typically in the context of post-inflationary reheating. In this talk, I will explore the possibility of preheating-like amplification of fluctuations of a scalar field following an electroweak first-order phase transition, which, unlike...
Understanding the intersection of particle physics and cosmology – dark matter – is a crucial open question in physics and cosmology. Here the goal is to construct a pipeline in which the implications of different dark matter models – from their particle nature to cosmological observations of large-scale structure (LSS) – can be systematically studied. Specifically, studying the (late-time)...
Detecting gravitational waves (GW) has given us new possibilities to probe the Universe. In this
talk, I will focus on the prospects of GW detection coming from cosmological supercooled phase
transition (PT) with the future generation of detectors, i.e. LISA/ET. Observation of such an event
will give us information about the physics of the early Universe.
In the standard model (SM), there...
At finite density and temperature, phase-quenched lattice simulations combined with perturbation theory provide a new precision approach to determine the thermodynamics of QCD in a wide arc of the phase-diagram where the strong coupling $\alpha_s$ remains small. However, in the cold and dense regime, phase-quenched lattice simulations exhibit a non-perturbative ground state due to quark...
Quark-gluon plasma (QGP) exists at temperatures of the order of 10^12 K (hundreds of MeV) and it is just a part of the larger QCD phase diagram. In current experiments, QGP is produced and studied colliding large nuclei (e.g. Lead-Lead) in the so called 'heavy-ion collisions' primarily carried on LHC and RHIC. Characterizing the various stages of the heavy-ion collisions is of utmost...
In this contribution, we emphasize the importance of the unitarity relation and $CP$ invariants in the computation of $CP$ asymmetries. We employ a diagrammatic approach based on holomorphic cutting rules, in which vacuum diagrams play a central role in systematically identifying all relevant asymmetry-generating processes. As a demonstration, we consider asymmetric semi-annihilations of a...
