相关论文: Confronting the Moduli-Induced LSP Problem
We consider a minimal extension of the Standard Model (SM), which leads to unification of the SM coupling constants, breaks electroweak symmetry dynamically by a new strongly coupled sector and leads to novel dark matter candidates. In this…
We develop a scenario whereby monopoles in a hidden sector yield a decaying dark matter candidate of interest for the PAMELA and FERMI $e^\pm$ excesses. The monopoles are not completely hidden due to a very small kinetic mixing and a hidden…
We consider a nonminimally coupled scalar field as a potential cold dark matter candidate. These models are natural extensions of the ultralight axion models which are based on minimally coupled scalar fields. Such ultralight scalar fields…
A brief review is given of dark matter in SUGRA, strings and branes. For SUGRA models the implications of Yukawa coupling unification on dark matter are discussed in the light of $g-2$ and $b\to s\gamma$ constraints. A brief discussion is…
Superstring theory, models with extra dimensions and other SUSY models generically predict that the coupling constants are in fact vacuum expectation values of fields like the dilaton, moduli etc. Assuming some of these fields are light…
We couple a sterile neutrino sector to a spin-3/2 particle and show that with a Planck reduced coupling, we can obtain a sufficiently long lifetime making the spin-3/2 particle a good dark matter candidate. We show that this dark matter…
Generically, string models with $N=1$ supersymmetry are not expected to have moduli beyond perturbation theory; stringy non-perturbative effects as well as low energy field-theoretic phenomena such as gluino condensation will lift any flat…
We study neutralino sectors in extensions of the MSSM that dynamically generate the mu-term. The extra neutralino states are superpartners of the Higgs singlets and/or additional gauge bosons. The extended models may have distinct lightest…
We introduce four supersymmetric (SUSY) axion models in which the strong CP problem and the $\mu$ problem are solved with the help of the Peccei-Quinn mechanism and the Kim-Nilles mechanism, respectively. The axion physics enriches the SUSY…
Slepton coannihilation is one of the most promising scenarios that can bring the predicted Dark Matter (DM) abundance in the the Minimal Supersymmetric Standard Model (MSSM) into agreement with the experimental observation. In this…
Heterotic orbifold compactifications yield a myriad of models that reproduce many properties of the supersymmetric extension of the standard model and provide potential solutions to persisting problems of high energy physics, such as the…
We investigate the gravitational production of superheavy scalar fields with nonminimal coupling during and after inflation. We derive analytical approximations using the mode function solution in a de Sitter background and also apply the…
We examine bounds on accelerated expansion in asymptotic regions of the moduli space in string theory compactifications to four spacetime dimensions. While there are conjectures that forbid or constrain accelerated expansion in such…
Deriving the Yukawa couplings and the resulting fermion masses and mixing angles of the Standard Model (SM) from a more fundamental theory remains one of the central outstanding problems in theoretical high-energy physics. It has long been…
We estimate the cosmological abundance of a modulus field that has dilatonic couplings to gauge fields, paying particular attention to thermal corrections on the modulus potential. We find that a certain amount of the modulus coherent…
The symmetric spaces that appear as moduli spaces in string theory and supergravity can be decomposed with explicit metrics using parabolic subgroups. The resulting isometry between the original moduli space and this decomposition can be…
In this talk I discuss some scenarios which involve small extensions of the ideas usually considered in the Minimal Supersymmetric Standard Model (MSSM). I present results of a study of the implication of non-universal gaugino masses (NGM)…
In recently introduced Split Susy theories, in which the scale of Susy breaking is very high, the requirement that the relic abundance of the Lightest SuperPartner (LSP) provides the Dark Matter of the Universe leads to the prediction of…
In supersymmetric axion models, if the gravitino or axino is the lightest SUSY particle (LSP), the other is often the next-to-LSP (NLSP). We investigate the cosmology of such a scenario and point out that the lifetime of the NLSP naturally…
A new theory of WIMP Dark Matter has been proposed, motivated directly by striking Data from the PAMELA and ATIC collaborations. The WIMP is taken to be charged under a hidden gauge symmetry G_Dark, broken near the GeV scale; this also…