IberiCos 2025

Session

Session 7 - Astroparticle Physics

15 Apr 2025, 14:30

Auditorium C.1

Conveners

Session 7 - Astroparticle Physics

• Session convener: Orfeu Bertolami

24. A multiple QCD axion

Maria Pestana Da Luz Pereira Ramos

15/04/2025, 14:30

Talk

The QCD axion is a well-motivated candidate for new physics and a primary focus of an ambitious global experimental program. It offers a compelling solution to both the strong CP and the dark matter problems within a narrow region of its parameter space, known as the QCD axion band. Nevertheless, rich theoretical frameworks lead us to expect that the axion is not the only exotic scalar...

40. Strong CMB bounds on ALPS form strings

Riccardo Impavido (Università di Ferrara, INFN Ferrara)

15/04/2025, 14:45

Talk

Axion-like particles (ALPS), radiated from a network of cosmic strings, may be a large part of Dark Matter (DM). In the era of precision cosmology, it is possible to characterize the effect of such particles - which almost scale invariant distribution function spans many orders of magnitudes in momentum - on the observables. In this work, we employ the CLASS code and Planck 2018 data to place...

52. Small instanton-induced flavor invariants and the axion potential

Guilherme Guedes (DESY)

15/04/2025, 15:00

Talk

Small instantons can enhance the axion mass, due to an appropriate modification of QCD in the ultraviolet (UV), in a way where the axion still solves the strong CP problem. However, besides increasing the axion mass, small instantons can also enhance any CP violation present in the theory, which can shift the minimum of the axion potential, putting the the axion solution strong CP problem at...

57. How much is the lifetime of an oscillon affected by coupling to another field?

Siyao Li

15/04/2025, 15:15

Talk

Oscillons are long-lived localized solitons of a real scalar field with potential flatter than quadratic. They are considered to be formed through parametric resonance during preheating after inflation and can play an important role in the early universe because of their long lifetime. However, their lifetime can be greatly affected by the parametric resonance if there is coupling of the...

31. Constraining dark matter candidates using gravitational strong lensing

Ioana Alexandra Zelko (Canadian Institute for Theoretical Astrophysics)

15/04/2025, 15:30

Talk

The nature of dark matter is one of the most important unsolved questions in science. Some dark matter candidates do not have sufficient nongravitational interactions to be probed in laboratory or accelerator experiments. It is thus important to develop astrophysical probes which can constrain or lead to a discovery of such candidates. I illustrate this using state-of-the-art measurements of...

43. Deviations from the von Laue Condition: Implications for the On-Shell Lagrangian of Particles and Fluids

Samuel Pinto (FCUP / CAUP)

15/04/2025, 15:45

Talk

According to the von Laue condition, the volume integral of the proper pressure inside isolated particles with a fixed structure and finite mass vanishes in the Minkowski limit of general relativity. We explore this condition considering a simple illustrative example: non-standard static global monopoles with finite energy, for which the von Laue condition is satisfied when the proper pressure...