We examine the virtual effects of Kaluza-Klein (KK) states on Higgs physics in universal extra dimension models. We study the partial widths Γh→gg, Γh→γγ , and Γh→γZ , which are relevant for Higgs production and detection in future collider experiments. These interactions occur at one loop in the Standard Model, as do the KK contributions. We find that the deviations induced by the KK exchanges...

In the Kaluza-Klein (KK) scenario with n large extra dimensions where gravity propagates in the 4+n dimensional bulk of spacetime while gauge and matter fields are confined to a four dimensional subspace, the light graviton KK modes can be produced in the Sun, red giants and supernovae. We study the energy-loss rates through photon-photon annihilation, electron-positron annihilation, gravi-Comp...

The question of whether the Kaluza-Klein (KK) graviphoton h 5µ and graviscalar h 55 are localized or not on the brane is one of the important issues. In this letter, we address this problem in five dimensions. Here we consider the massless (zero-mode) propagations without requiring the Z 2-symmetry on h 5µ. We obtain the graviton h µν , graviphoton, and graviscalar exchange amplitudes on shell....

We summarize the main features of several dark matter candidates in extra-dimensional theories. In particular, we review Kaluza-Klein (KK) gravitons in universal extra dimensions and branons in brane-world models. KK gravitons are superWIMP (superweakly-interacting massive particle) dark matter, and branons are WIMP (weakly-interacting massive particle) dark matter. Both dark matter candidates ...

We examine the phenomenological consequences of a supersymmetric bulk in the scenario of large extra dimensions. We assume supersymmetry is realized in the bulk and study the interactions of the resulting bulk gravitino Kaluza-Klein (KK) tower of states, with supersymmetry breaking on the brane inducing a light mass for the zeromode gravitino. We derive the 4-d effective theory, including the c...

We consider the analytic continuation of $(p+q)$-dimensional Minkowski space (with $p$ and $q$ even) to $(p,q)$-signature, study conformal boundary resulting "Klein space". Unlike familiar $(-+++..)$ signature, now null infinity ${\mathcal I}$ has only one connected component. The spatial timelike infinities ($i^0$ $i'$) are quotients generalizations AdS spaces non-standard signature. Together,...