Seminar Room. Department of Physics, UPV/EHU 

BILBAO, Dec. 16th, 2022

Confirmed Speakers:

  • 10:00 am

    • Tanmay Vachaspati (Arizona State University, USA)
      • ” Schwinger pair production and non-Abelian electric fields”.
        An electric field in pure Maxwell theory is stable. However, if there are charged particles in the theory, the electric field decays due to Schwinger pair production. In pure non-Abelian gauge theories, the gauge particles are themselves charged, leading to the question whether a non-Abelian electric field, such as in a confining string, can be stable. I will discuss electric fields due to certain non-Abelian gauge configurations that are protected from Schwinger pair production and may be candidates for “electric strings”.

  • 11:00 am

    • Evangelos Sfakianakis (IFAE, Spain)
      • “Theory and Phenomenology of oscillons”.
        Oscillons are ubiquitous in scalar field models where the potential is shallower than quadratic away from the origin. They have been shown to arise naturally after inflation with plateau or axion monodromy potentials and their formation is accompanied by the emission of gravitational waves. I will show how the spectrum of GW’s retains the memory of oscillon formation in some cases, providing a first tool —at least in principle— of probing the inflationary potential around the origin. Despite the wide belief that multiple fields are present in the early universe, oscillon studies have largely relied on single-field models. I will describe a first step towards understanding  multi-field oscillons, albeit in a simple highly symmetric model. I will present a semi-analytical method for constructing oscillon solutions as well as discuss their formation from the fragmentation of a scalar condensate.

  • 12:00 pm

    • Coffee Break

  • 12:30 pm

    • Josu Aurrekoetxea (Oxford, UK)
      • ” Fundamental physics from the strong-field regime of gravity”.

        We are in a new era of gravitational physics in which both gravitational-wave measurements and cosmological observations can be used to test fundamental physics. Moreover, recent computational developments allow us to investigate (at present largely unexplored) regimes where the gravitational force is strong – a very promising area to search for new physics. In this talk I will overview two cases in which we aim to use strong-gravity to learn about the dark components of the universe: the interaction of binary black hole mergers with their dark matter environments and the emission and propagation of scalar gravitational waves, a distinct signature of theories beyond GR aiming to explain dark energy.

Organizing Committee:
Ana Achucarro
Jose J. Blanco-Pillado
Daniel Jimenez-Aguilar
Joanes Lizarraga
Asier Lopez-Eiguren
Ander Urio
Jon Urrestilla