VI – Cosmological Olentzero Workshop
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 nonAbelian 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 nonAbelian gauge theories, the gauge particles are themselves charged, leading to the question whether a nonAbelian electric field, such as in a confining string, can be stable. I will discuss electric fields due to certain nonAbelian 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 singlefield models. I will describe a first step towards understanding multifield oscillons, albeit in a simple highly symmetric model. I will present a semianalytical 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 strongfield regime of gravity”.
We are in a new era of gravitational physics in which both gravitationalwave 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 stronggravity 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.



13:30 pm

END
Download the poster for the VI Olentzero Workshop here.

Organizing Committee:
Ana Achucarro
Jose J. BlancoPillado
Daniel JimenezAguilar
Joanes Lizarraga
Asier LopezEiguren
Ander Urio
Jon Urrestilla