14th International Symposium on Particles, Strings and Cosmology (PASCOS '08)
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 $osp(1|32)$.\'
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.