Nuevas Tendencias en Teoría Cuántica de Campos

Almost two decades ago, I was fortunate to contribute to the study of the singular structure of QCD amplitudes in perturbation theory. In particular, we could look with new eyes into the factorization of QCD scattering amplitudes, which provides a crucial template for the calculation of relevant observables for lepton and hadron collider phenomenology. In this talk I will review how some of these ideas have been implemented for in-medium QCD amplitudes in heavy-ion collider phenomenology and I will highlight the tools used in extreme QCD, that may help further our understanding of factorization of QCD amplitudes under these conditions.

Quantum corrections to physical observables in High Energy Physics are computed by means of perturbative Quantum Field Theory. Within the framework of pertubative QCD, the study of multi loops and legs is becoming crucial to understand the physics of fundamental particles and its interactions. Along the years, several methods have been developed to overcome the ill-defined quantities that appear in any multiloop calculation. In this talk, we review the Four Dimensional Unsubtraction, a new algorithm based on the Loop- Tree Duality theorem to compute accurate theoretical predictions in four space-time dimensions.

Entanglement, whose usefulness as an experimental resource has long been understood by the quantum information community, has deeply impacted theoretical high energy and gravity research in the past 15 years. On the one hand, it sheds valuable light on the dynamics of quantum field theories. On the other hand, in the context of holographic duality, a very profound link has been discovered between entanglement and gravity. In this talk we will very briefly review a few
of these developments.

In this talk we review our spinor-like construction for the QFT for massive fields transforming in the (1,0)+(0,1) representation of the HLG. The chiral properties of these fields lead us to consider the possibility that dark matter transforms in this representation. We work out the corresponding effective theory for the interactions with standard model fields and the predictions for dark matter relic density and observables in direct and indirect searches of dark matter.

I will give a short summary of what is presently known about radiative corrections to the Euler-Heisenberg Lagrangian
in QED in 3+1 and 1+1 dimensions, and what information can be obtained from them on the large-order asymptotic structure of QED.

Originally a statement for scattering amplitudes in gauge and gravity theories, the double copy has recently been shown to also apply to classical systems, such as black holes. In this talk, I will review some incarnations of the classical double copy,
and will comment on the seemingly fantastic question "What is the square root of a black hole?".

In this talk I discuss the helicity method for massive gravitino amplitudes, and apply them to calculate the 2-,3- and 4-body decays of the stop in a scenario where the gravitino is the LSP, and thus a dark matter candidate.