The detection of gravitational waves associated with short GRBs and observations of the TeV photons from very energetic events were the main breakthroughs in the gamma-ray burst field in recent years. I will discuss the theoretical progress in modelling of prompt GRB emission based on the recent multi-wavelength observations, including the lepto-hadronic model, the low energy spectral slopes under the assumption of the decaying magnetic field, the emission from structured GRB jets, and the soft-X-ray emission from dust-scattering halo.

A grassroots initiative “Striving towards Environmental Sustainability in High Energy Physics, Cosmology and Astroparticle Physics” originated in 2021 following an online workshop. It later adopted the HECAP+ acronym to include Hadron and Nuclear Physics as well. These communities make use of common experimental infrastructure, such as accelerators and observatories, and share similar computing needs. They thus face similar challenges to improving the sustainability of their research. In this talk, we describe how the initiative was started and present its main output so far, a reflection document. It considers the environmental impacts of HECAP+ research, highlights best practices, makes recommendations for positive changes and identifies opportunities and challenges relating these changes to broader aspects of social responsibility.

TBD

Since the discovery of the Higgs boson, particle physics has faced a notable slowdown. Despite initial optimism, subsequent efforts to uncover new particles, like those predicted by supersymmetry or axion dark matter, have yielded limited results. In response to these challenges, this presentation advocates for a paradigm shift toward cosmology as a promising frontier for exploring high-energy physics. The wealth of data, independent datasets, controlled systematics on the observational side, coupled with precise, model-independent and falsifiable predictions on the theoretical side, all constitute invaluable assets. Specifically, this discussion will focus on two facets of precision physics with cosmology: already existing constraints on the primordial power spectra from cosmic microwave background observations, and the possibilities offered by upcoming large-scale-structure experiments to describe primordial non-Gaussianities. These endeavors promise insights into the precise properties of particle content during inflation, heralding a new era of discovery at the intersection of high-energy physics and cosmology.

Tunneling in quantum mechanics is a standard illustration of quantum phenomena, distinguished by exponentially decaying solutions within classically forbidden zones. Within the realm of relativistic quantum mechanics, a more intriguing phenomenon than regular quantum tunneling arises – Klein tunneling. This phenomenon involves non-decaying oscillating solutions in classically forbidden areas known as supercritical barriers, characterized by strong fields capable of creating pairs of particles and anti-particles.

In this presentation I will introduce the dynamics governing Klein tunneling exhibited by fermions and bosons in both frameworks of the first quantized and the second quantized theories. In the first quantized theory, the phenomenon is elucidated through the multiple scattering expansion, which converges for fermions but diverges for bosons, providing a partial account of pair creation. Validation of our results is achieved through numerical solutions employing the finite difference method and the split operator method. However, a paradox emerges in the fermionic case, defying resolution within the first quantized framework.

Within the second quantized framework, we use a computational Quantum Field Theory approach in order to account for the pair creation phenomenon. Additionally, we resolve the fermionic paradox by invoking the Pauli blockade. We find that particles do not actually "tunnel" through the supercritical barrier. Instead, it is the modulation of the number densities of created anti-particles (increase for bosons and decrease for fermions) that is responsible for the generation of the "tunneled" particle outside the barrier.

Fundamental electric dipole moments (EDM) are powerful low-energy probes [1] in the search for New Physics and an important
complement to searches using high-energy particle colliders. In particular, the existence of lepton EDMs imply the
violation of charge-parity (CP) symmetry beyond that already known and implemented into the Standard Model of elementary
particles. The discovery of a fundamental EDM could therefore offer a viable mechanism for explaining the observed dissymmetry
between matter and antimatter in our universe.

In the talk I will focus on the particularly promising search for the electron EDM. After several decades of using heavy
atoms as low-energy probes, the most stringent upper bounds on the electron EDM are today obtained from collaborative work of
experimentalists and theorists using diatomic molecules. After a survey of the state of the art I will present an ongoing
effort [2] employing the molecule radium-silver (RaAg), so far never created in a laboratory, which has the potential of
increasing the current sensitivity of electron EDM probes by 3-4 orders of magnitude.

[1] R. Alarcon et al., arXiv: 2203.08103 [hep-ph] (2022)
[2] T. F., D. DeMille, New J. Phys. 23 (2021) 113039

Starting with the basic properties of pulsars and their pulses, we go through the methodology underlying pulsar timing observations. We discuss the data analysis methods used to process timing residuals, the new evidence suggesting the detection of a SBGW and its possible cosmological interpretations. In particular, we will take the example of cosmic strings as a possible early Universe interpretation.

Rotation and convection have important consequences for stellar internal structure and evolution. On the first side, rotation, through the centrifugal acceleration, deforms the star and counteracts the gravitational force, mimicking a lower mass star. Most importantly, meridional circulations and rotation-induced turbulence mix chemical elements, extending the life of the star and affecting stellar age determinations, one of the most important problems in astrophysics. Lastly, the interaction between rotation and convection generates magnetic fields, maintaining a dynamo and influencing on the survival of stellar atmospheres. Important effort have been devoted to improving the rotation modelling in the stellar evolution code Cesam2k20 (formerly known as CESTAM).It now accounts for the effect of 2D geometry of a star distorted by rotation, making it a framework to test all the processes envisaged to transport angular momentum.
On the 2nd side, convection is poorly modelled in stellar evolution code. From a highly turbulent process, it is often reduced to a laminar flow, whose energy flux is controlled by a unique free parameter, fixed along evolution. The value of this paramter is not physically constrains, but has a strong impact on estimation of stellar global properties. A new method, the entropy callibration, was developped to constrain the value of the convection parameter with prescription of entropy in the deep convective zone, obtained from 3D simulations of stellar atmospheres. With the entropy calibration, now available in Cesam2k20, the convection parameter vary along evolution, and is linked to physical quantities, removing an important source of uncertainties.

Over the past decade, the landscape of academic publishing has changed dramatically, with publishers moving from subscription-based models to "open access" in which papers are
available to read free of charge. Many journals have made the decision to maintain revenue by
charging authors for this, via so-called "Article Processing Charges" (APCs) which can run to $1000s, thereby closing the door on those without funds to pay. More recently, there have been moves to encourage researchers to publish using "Diamond" Open Access wherein papers are published without charge to the authors and without cost to the reader. In this talk I shall discuss the ennvironment for Open Access Publishing in Astrophysics with reference to the Open Journal of Astrophysics (OJAp), which offers a not-for-profit service of this kind using an arXiv-overlay model. I will also offer a possible vision of the future of truly "Open Access" publishing based on a global network of institutional and/or subject-based repositories.