Ilya L. Shapiro, “Local and nonlocal models of quantum gravity” 🗓

The main difficulty of perturbative quantum gravity (QG) in D=4 dimensions is the conflict between renormalizability and unitarity of the theory. The simplest version of QG is based on General Relativity and turns out to be nonrenormalizable. One can construct renormalizable and even superrenormalizable versions of QG by introducing higher derivatives. In the local versions of higher derivative models of QG there are always unphysical higherderivative massive unphysical ghosts. One can construct non-polynomial in derivatives (or, equivalently, nonlocal) models of QG, which have no ghosts at the tree level. However, taking loop corrections into account one meets infinite amount of ghost-like complex states. The theories of both local and nonlocal types attracted a lot of attention in the last years and our purpose it to present a brief review of the problems and perspectives of these models, according to the present-day understanding.

Saturnalia 2019: calendario de charlas para la próxima semana

Se ha creado una página indico para el workshop Saturnalia: https://indico.capa.unizar.es/event/4/

Además, puedes añadir el calendario de charlas a tu aplicación de calendario mediante el siguiente enlace:
https://calendar.google.com/calendar/b/1?cid=ODA4c2NlNzVkZmx1MGE5dm9hb3YxdXRpbWtAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ

Hemos solicitado a los conferenciantes que al menos la primera mitad de las charlas sean de un nivel accesible, de modo que los estudiantes del Grado en Física son bienvenidos.

Conferencia de Antonio Pich, “El bosón de Higgs: una ventana en la frontera del conocimiento” 🗓 🗺

El descubrimiento en 2012 del bosón de Higgs, en el “Gran Colisionador de Hadrones” (LHC) del CERN, tiene para la física una relevancia equiparable a la que tuvo el descubrimiento del ADN en biología o la evidencia de la estructura atómica y molecular en química. Desde el punto de vista tecnológico supone un hito comparable a la llegada del hombre a la Luna, pero sus repercusiones científicas son mucho más importantes. Una hipótesis teórica, formulada en 1964 para poder entender las masas de los constituyentes elementales de la materia, se confirmaba 48 años más tarde como un ingrediente tangible del mundo real: un nuevo campo de fuerzas que puede hacer encajar las últimas piezas del llamado “Modelo Estándar” de las interacciones fundamentales y, quizás, abrir una ventana a nuevos fenómenos de naturaleza insospechada. El LHC, una auténtica maravilla tecnológica, sigue explorando las fronteras actuales del conocimiento y, en particular, las propiedades del campo de Higgs. Estamos inmersos en una etapa apasionante de investigación científica que puede deparar grandes sorpresas.

Jan Schütte-Enge, “Axion dark matter direct detection: Present and Future” 🗓 🗺

Axions are hypothetical particles introduced to solve the strong CP problem of the Standard Model. In addition axions can resolve the dark matter mystery. In this talk I will first discuss the interesting axion mass ranges which current and future direct detection experiments are targeting. I will then focus on two different detection techniques for dark matter axions. First I will discuss open axion haloscopes, such as dish antennas and dielectric haloscopes. We developed two calculation techniques to compute the fields in open axion haloscopes explicitly in 3D. These 3D techniques are needed for a reliable sensitivity estimate. I show how one can use our methods to calculate axion velocity effects and the influence of several experimental imperfections. The second part of my talk deals with axions that are realized in condensed matter systems. I will first outline an idea how one can detect them. Finally I discuss how axions, that are realized in condensed matter systems, can be used to detect dark matter axions

Ponente: Jan Schütte-Enge (Universidad de Hamburgo)

Carlos García Canal, “Probing strong dynamics with cosmic neutrinos” 🗓

Triggered by the IceCube detection of astrophysical neutrino candidates in the range of PeV energies, we propose to investigate the sensitivity of future South Pole neutrino-detection experiments to the neutrino-nucleon cross section. By using the combination of up- and down-going data of neutrinos, sensible to neutral current processes one can disentangle particle physics from astrophysics and constrain the neutrino interactions.In particular, we show that IceCube-Gen2 will be able to determine the neutrino-nucleon cross section with a precisión comparable to the perturbative QCD informed by collider data and eventually to detect new physics.

Ponente: Carlos García Canal (Universidad de la Plata, Argentina)