PLANCK2024

Session

Parallel Session PI.8

4 Jun 2024, 16:40

Anfiteatro Abreu Faro (IST, Lisboa)

Conveners

Parallel Session PI.8

• Javier Rubio

326. Shedding light on the $\Delta m^2_{21}$ tension with supernova neutrinos

Rasmi Muñoz

04/06/2024, 16:40

One long-standing tension in the determination of neutrino parameters is the mismatched value of the solar mass square difference, $\Delta m_{21}^2$, measured by different experiments: the reactor antineutrino experiment KamLAND finds a best fit larger than the one obtained with solar neutrino data. Even if the current tension is mild ($\sim 1.5\sigma$), it is timely to explore if independent...

263. Geometric (p)reheating of the Universe

Nicolás Loayza (IFIC - Universitat de Valéncia - CSIC)

04/06/2024, 17:00

We study the energy transfer after inflation from the inflaton ($\phi$) into a scalar field ($\chi$) non-minimally coupled to gravity via $\xi R|\chi|^2$, considering single field inflationary models with potential $\propto |\phi|^{p}$ around $\phi = 0$. This corresponds to the paradigm of geometric preheating, which we extend to its non linear regime by means of lattice simulations. Using...

244. Energy distribution and equation of state during and after tachyonic preheating

Kenneth Marschall

04/06/2024, 17:20

We discuss the evolution of the energy distribution and equation of state during the reheating phase. We consider observationally consistent single-field inflation models, with potentials that have monomial shape around the origin and a reheating sector that comprises a massless scalar field, which couples via a trilinear interaction to the inflaton. By investigating the non-linear dynamics of...

212. Emergent particles of a de Sitter universe: Thermal interpretation of the stochastic formalism and beyond

Dr TaeHun Kim (KIAS)

04/06/2024, 17:40

A thermal interpretation of the stochastic formalism of a slow-rolling scalar field in a de Sitter (dS) universe is given. We construct a correspondence between causal patches in the 3-dimensional space of a dS universe and particles living in an abstract space. By assuming a dual description of scalar fields and classical mechanics in the abstract space, we show that the stochastic evolution...

248. Probing Reheating with Graviton Bremsstrahlung

Dr Yong Xu (JGU Mainz)

04/06/2024, 18:00

In this talk, I will discuss the inevitable stochastic gravitational wave (GW) spectrum resulting from graviton bremsstrahlung during inflationary reheating. We will focus on an inflaton, denoted as $\phi$, oscillating around a generic monomial potential $V(\phi) \propto \phi^n$, while considering two different reheating scenarios: (i) inflaton decay and (ii) inflaton annihilation. I will...

216. Black Hole Quadratic Quasi-Normal Modes

Bruno Bucciotti (Scuola Normale Superiore di Pisa)

04/06/2024, 18:20

We study the quadratic quasi-normal modes of a Schwarzschild black hole, i.e. those perturbations that originate from the coupling of two (linear) quasi-normal modes.
Assuming the amplitude of the two linear modes is known, we compute the amplitude of the resulting quadratic mode for a wide range of possible angular momenta. Finally, we reconstruct the waveform in radiation gauge.

299. Nonlocal field theories and nonlocal gravitational models

Fabio Briscese

04/06/2024, 18:40

Nonlocal field theories allow us to formulate a quantum renormalizable theory of the gravitational field, thanks to an improved ultraviolet convergence of the quantum propagator. In this talk, I will describe the main features of these models, such as renormalizability and quantum unitarity. Additionally, I will discuss some properties of classical solutions of the modified Einstein's equations.