HEP2023 - 40th Conference on Recent Developments in High Energy Physics and Cosmology, Ioannina, Greece

Session

Parallel (Theory)

3

5 Apr 2023, 17:00

Main Auditorium (Conference Centre “Karolos Papoulias”)

Conveners

Parallel (Theory)

• KONSTANTINOS DIMOPOULOS (LANCASTER UNIVERSITY)

Parallel (Theory)

• Athanasios Dedes (University of Ioannina)

75. Heavier tail likelihoods for robustness against data outliers; Applications to the analysis of Gravitational Wave data

Argyro Sasli (Aristotle University of Thessaloniki)

05/04/2023, 17:00

In recent years we have been witnesses of the blooming of Gravitational Wave Astronomy. In the near future, with the more advanced, as well as the space-based detectors coming online, it is expected to detect events originating from compact binary objects at much higher rates. One of the future data analysis challenges, is performing robust statistical analyses in the presence of detector...

60. Ending inflation with a bang: Higgs vacuum decay in $R + R^2$ gravity

Dr Andreas Mantziris (University of Warsaw)

05/04/2023, 17:20

According to the current experimental data, the Higgs vacuum appears to be metastable due to the development of a second lower ground state in its potential. Consequently, vacuum decay would induce the nucleation of true vacuum bubbles with catastrophic consequences for our Universe and therefore we are motivated to study possible stabilising mechanisms in the early universe. In our latest...

9. Black hole solutions In Chern-Simons Gravity with Axion Hair

Nikos Chatzifotis (National Technical University of Athens)

05/04/2023, 17:40

Chern-Simons gravity with axions is revisited from the point of view of studying Kerr-like black hole solutions which take into account the back reaction of the axion field onto the spacetime geometry. We extend previous results by giving analytic expressions for slowly rotating black holes, which formally include an all order expansion in the pertinent coupling constant. We investigate...

11. On Thermal Stability of Hairy Black Holes

Panagiotis Dorlis

05/04/2023, 18:00

We discuss thermodynamical stability of black hole spacetimes, with the latter viewed as defects in the thermodynamical parameter space. We derive, in a model independent way, the conditions for a hairy black hole with a secondary hair to reach a stable thermal equilibrium with the heat bath, which the black hole is embedded to. As a specific example, we consider black holes with scalar hair...

71. How Large can the SUSY Contributions to $b\to s\ell^+\ell^-$ Processes be?

Mr Kostas Mantzaropoulos (University of Ioannina)

05/04/2023, 18:20

We examine how large the effects in $b\to s\ell^+\ell^-$ transitions in the MSSM with a general flavour structure can be. After carefully analyzing all potentially important supersymmetric contributions, we find that the largest effects arise in case of a light wino, a light smuon and muon sneutrino, a relatively light left stop, maximal mixing among left-handed down-squarks of the $2^{\rm...

59. T-Model Higgs Inflation In Supergravity

Constantinos Pallis (Aristotle University of Thessaloniki)

07/04/2023, 17:00

We propose a modification of no-scale supergravity models which incorporates sgoldstino stabilization and supersymmetry (SUSY) breaking with a tunable cosmological constant by introducing a Kahler potential which yields a kinetic pole of order one. The resulting scalar potential may develop an inflection point close to which an inflationary period can be realized for subplanckian field values...

1. Anomalous and axial Z' contributions to g-2

Dr Pascal Anastasopoulos (HEPHY)

07/04/2023, 17:20

We will study the effects of an anomalous Z' boson on the anomalous magnetic moment of the muon (g-2), and especially the impact of its axial coupling. We mainly evaluate the negative contribution to (g-2) of such couplings at one-loop and look at the anomalous couplings generated at two loops. We find areas of the parameter space, where the anomalous contribution becomes comparable and even...

79. Aspects of Relativistic and Carrollian fluids

Konstantinos Siampos (National and Kapodistrian University of Athens (GR))

07/04/2023, 17:40

We study Carrollian hydrodynamics on arbitrary backgrounds by employing two distinct but complementary paths. The first one is Carrollian diffeomorphism invariance while the second one consists in analyzing the relativistic fluid equations at small speed of light. The results of the method agree, but the second approach is superior as it effortlessly captures more elaborate situations with...

2. Goldstino condensation

Fotis Farakos

07/04/2023, 18:00

We investigate the formation of composite states of the goldstino in theories with non-linearly realized supersymmetry and show that the pure Volkov-Akulov model has an instability towards goldstino condensation. We discuss the limitations and implications of our findings for string models involving anti-brane uplifts.

70. Compact objects in gravity theories

Dr Athanasios Bakopoulos (National Technical University of Athens)

07/04/2023, 18:20

We analyse in all generality beyond Horndeski theories of shift symmetry in a static and spherically symmetric spacetime. By introducing four auxiliary functions, we write the field equations in a particularly compact form. We show that assuming additionally parity symmetry renders the system directly integrable giving multiple families of black-hole solutions. These have typically an...

66. Universal Relations for rapidly rotating neutron stars using supervized machine learning techniques

Mr Grigorios Papigkiotis (Aristotle University of Thessaloniki, Department of physics)

07/04/2023, 18:40

Neutron stars are some of the most fascinating stellar objects in the universe, offering unique opportunities to study fundamental physics at supra-nuclear densities. However, their internal structure remains poorly known due to the uncertainties in the equation of state (EoS). In recent years, a lot of work has revealed the existence of universal relations between various observable...