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.
In SUGRA flavour models, a total sequestering is not possible and an irreducible amount of flavour and CP violation is essentially unavoidable, which renders many flavour models testable in the near future experiments.
Working in the weak tachyon region of a condensing tachyon background, we find the modified equations of motion for massless strings with conformal perturbation theory. We then estimate the backreaction on the background dilaton. In large (supercritical) dimensions, we find that the backreaction can be significant in a large region of spacetime.
WIMP dark matter candidates chi^0 have interesting signatures for direct and indirect detection in regimes where there is a near degeneracy with a heavier charged state chi^{pm}, as occurs for example along the boundary of the coannihilation strip in the CMSSM. For small splittings of O(10) MeV, the scattering of WIMPs off nuclei may be dominated by inelastic recombination processes mediated by the formation of (chi^- N) bound states, leading for example to a distinct signature for direct detection.
Parametric resonance, also known as preheating, is a plausible mechanism for bringing about the transition between the inflationary phase and a hot, radiation dominated universe. This epoch results in the rapid production of heavy particles far from thermal equilibrium and has the potential to source a significant stochastic background of gravitational radiation. Here, I present a numerical algorithm for computing the contemporary power spectrum of gravity waves generated in this post-inflationary phase transition for a large class of scalar-field driven inflationary models.
We show the nature of sequestering hidden sector in five-dimensional supergravity models, where a negative vacuum energy of the nonperturbative modulus potential is canceled by a dynamically generated F-term in the hidden sector. Soft supersymmetry breaking terms are explicitly shown in the case that both the visible and the hidden sector is quasi-localized in the extra dimension.
The phenomenology of TeV-scale physics can be modified by the existence of scale-invariant \'unparticle\' fields that can couple to the standard model sector. In particular, it has been shown that unparticles can alter gravitational interactions in a similar fashion to extra dimensions. Observable results from this mechanism -- most notably mini-black hole formation -- will be discussed, and methods of differentiating unparticles from extra dimensional models will be addressed.
If inflation is to be considered in an unbiased way, as possibly originating from one of a wide range of underlying theories,then observations need not be simply applied to reconstructing the inflaton potential, V(phi), or a specific kinetic term, as in DBI inflation, but rather to reconstruct the inflationary action in its entirety. I will discuss the constraints that can be placed on a generalsingle field action from measurements of the primordial scalar and tensor fluctuation power spectra and non-Gaussianities.
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 $osp(1|32)$.\'
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