Since 2002 Perimeter Institute has been recording seminars, conference talks, and public outreach events using video cameras installed in our lecture theatres. Perimeter now has 7 formal presentation spaces for its many scientific conferences, seminars, workshops and educational outreach activities, all with advanced audio-visual technical capabilities. Recordings of events in these areas are all available On-Demand from this Video Library and on Perimeter Institute Recorded Seminar Archive (PIRSA). PIRSA is a permanent, free, searchable, and citable archive of recorded seminars from relevant bodies in physics. This resource has been partially modelled after Cornell University's arXiv.org.
We study the effects of boundary terms in models with a flat \'Universal\'\' Extra Dimension in which all Standard Model fields propagate in the bulk. We show how non-minimal boundary terms change the mass spectrum and interactions of Kaluza-Klein modes, allow for new dark matter candidates from UED, and how they alter collider phenomenology.
Many string theorists and cosmologists have recently turned their attention to building and testing string theory models of inflation. One of the main goals is to find novel features that could distinguish stringy models from their field theoretic counterparts. This is difficult because, in most examples, string theory is used to derived an effective theory operating at energies well below the string scale.
\'BPS preons were conjectured (PRL 86, 4451 (2001), hep-th/0101113) as the basic constituents of M-theory; they are states preserving 31/32 supersymmetries. We discuss the absence of preonic solutions in D=10,11 supergravities and its possible implications. The AdS generalization of the BPS preons, the AdS preons defined over an AdS vacuum, will also be discussed. This leads to the {it AdS-M-algebra}, a deformation of the M-algebra which is identifed as $osp(1|32)$.\'
I will present extensions of hybrid inflationary models in the context of supersymmetric D-term in- flation. I will show that there exists a large domain of parameters in which significant primordial non-Gaussianities can be produced while preserving a scale free power spectrum for the metric fluctuations. In particular I will explicitly present the expected bi- and trispectrum for such models and compared the results to the current and expected observational constraints.
In supersymmetric (SUSY) models with the gravitino being the lightest SUSY particle (LSP), the SUSY breaking scale (i.e., the gravitino mass) could be determined by measuring the lifetime of the next-to-lightest SUSY particle (NLSP). However, for an ultralight gravitino of mass of O(1) eV, which is favored cosmologically, the determination of the SUSY breaking scale, or the gravitino mass, is difficult because the NLSP decay length is too short to be measured directly.
We further advance the application of the Canny algorithm for detecting cosmic strings in CMB maps.
We first discuss the possibility of getting a non-supersymmetric dS minimum with the inclusion of perturbative and non-perturbative alpha\' corrections and instanton contributions in the large volume limit of certain Swiss Cheese Calabi Yau orientifold type IIB compactifications. We then discuss axionic slow roll inflation with the NS-NS axions providing a flat direction for slow-roll inflation to proceed from a saddle point to the nearest dS minimum.
In the last years, the NA48/2 experiment at the CERN SPS has recorded an unprecedented sample of charged kaon decays. From this, we report very precise measurements of fundamental parameters of Chiral Perturbation Theory (ChPT) and the study of low energy pi-pi scattering. Several rare and very rare decays have been studied. From more than 10^6 K+- -> pi+ pi0 gamma decays, a first measurement of the interference between Bremsstrahlung and Direct Emission amplitudes and a stringent limit on direct CP violation in this channel is presented.
We study observables in a conformal field theory which are very closely related to the ones used to describe hadronic events at colliders. We focus on the correlation functions of the energies deposited on calorimeters placed at a large distance from the collision. We consider initial states produced by an operator insertion and we study some general properties of the energy correlation functions for conformal field theories. We argue that the small angle singularities of energy correlation functions are controlled by the twist of non-local light-ray operators with a definite spin.
Astrophysical evidence indicates that the universe consists to about 25% of non-baryonic, cold Dark Matter, compared to merely ~4% of \'regular\' matter, composed of quarks and electrons. The existence of Dark Matter and Dark Energy is striking evidence for physics beyond the Standard Model, and understanding their nature ranks among the foremost questions in science today. If the bulk of matter in the universe consists of relic massive particles moving at non-relativistic speeds, we may be able to detect these particles in direct searches with low background experiments.