Talks

We will review the definitions of spin foam models for quantum gravity and the recent advances in this field, such as the "graviton propagator", the definition of coherent states of geometry and the derivation of non-commutative field theories as describing the effective dynamics of matter coupled to quantum gravity. I will insist on the role of group field theories as providing a non-perturbative definition of spinfoams and their intricate relation with non-commutative geometry and matrix models.

It has recently uncovered that the intertwiner space for LQG carries a natural representation of the U(N) unitary group. I will describe this U(N) action in details and show how it can be used to compute the LQG black hole entropy, to define coherent intertwiner states and to reformulate the LQG dynamics in new terms.

We describe a class of non-Fermi liquid systems, using the AdS/CFT correspondence. The Fermi surfaces are studied by computing the response functions of fermionic operators. The scaling behavior near the Fermi surfaces is determined by conformal dimensions in an emergent IR CFT. The low-energy excitations near the Fermi momenta are not Landau quasiparticles. When the operator is marginal in the IR CFT, the full spectral function is precisely of the `marginal Fermi liquid' form, introduced as a phenomenological model of the `strange metal' phase of high temperature superconductors.

The sneutrino is a viable NLSP candidate in SUSY with gravitino LSP. In my talk I will focus on this possibility, in particular concentrating on the question of whether the LHC can distinguish spectra with a sneutrino NLSP from alternatives, e.g. ones with neutralino LSP. I will show that there are at least two different families of experimentally allowed spectra with sneutrino NLSP which exhibit distinctive multilepton signals. These spectra are not easy to fake within the MSSM. I will discuss these signals in detail and illustrate our analysis approach on simulations.