14086679
Implication of Brane fluctuations to indirect collider signals
We study the effect of brane fluctuation on the indirect signals of high energy colliders. Brane fluctuation could act as a regulator of divergent expression of infinite tower of Kaluza-Klein graviton effects. The phenomenological parameter λ, introduced by Hewett, is shown to be determined in our setting, and its dramatic behaviors depending on the D = 4+δ dimensional gravitation scale MD, `softening parameter' Δ, and (s)1/2 of collider are presented. The present exclusion bounds from the processes e+e−→γγ and p→e+e−,γγ(γ) are considered within the parameter space (MD,Δ) with respect to the number of extra dimensions.
14695226
Rotating Black Holes at Future Colliders
We consider the production and decay of TeV-scale black holes. Evaluation of the production cross section of higher dimensional rotating black holes is made. The master field equation for general spin-$s$ fields confined on brane world is derived. For five-dimensional (Randall-Sundrum) black holes, we obtain analytic formulae for the greybody factors in low frequency expansion.
122705764
Phenomenology of the heavy B H in a littlest Higgs model
125886851
Rotating black holes at colliders
119338290
Neutrino Mass from R-parity Violation in Split Supersymmetry
We investigate how the observed neutrino data can be accommodated by R-parity violation in Split Supersymmetry. The atmospheric neutrino mass and mixing are explained by the bilinear parameters ξi inducing the neutrino-neutralino mixing as in the usual low-energy supersymmetry. Among various one-loop corrections, only the quark-squark exchanging diagrams involving the order-one trilinear couplings λ'i23,i32 can generate the solar neutrino mass and mixing if the scalar mass mS is not larger than 109 GeV. This scheme requires an unpleasant hierarchical structure of the couplings, e.g., λi23,i32 ~ 1, λ'i3310−4 and ξi10−6. On the other hand, the model has a distinct collider signature of the lightest neutralino which can decay only to the final states, liW(*) and νZ(*), arising from the bilinear mixing. Thus, the measurement of the ratio; Γ(eW(*)):Γ(μW(*)):Γ(τW(*)) would provide a clean probe of the small reactor and large atmospheric neutrino mixing angles as far as the neutralino mass is larger than 62 GeV.
16076999
Minimal extra dimensional cosmology from hidden sector gauge theory
We build a minimal cosmological model in higher dimensions based on a hidden sector gauge theory, which is less constrained by the low energy experiments. In this model we introduce the minimal non-Abelian gauge symmetry SU(2) in the fifth spatial dimension. The inflaton field which is identified as a part of higher dimensional gauge boson is protected by the gauge symmetry. Thus the inflaton potential is fully radiatively generated by the gauge self interaction alone without introducing any ad hoc field. and is flat enough to drive slow-roll inflation. We find that in the regime of perturbative gauge interaction and large compactification radius the anticipated magnitude of the curvature perturbation power spectrum and the value of the corresponding spectral index are in perfect agreement with the recent observations in a wide range of the model parameters. The model also predicts a large fraction of the gravitational waves, negligible non-Gaussianity, and high enough reheating temperature.
119287976
Solving the Effective Field Equations for the Newtonian Potential
Loop corrections to the gravitational potential are usually inferred from scattering amplitudes, which seems quite different from how the linearized Einstein equations are solved with a static, point mass to give the classical potential. In this study we show how the Schwinger–Keldysh effective field equations can be used to compute loop corrections to the potential in a way which parallels the classical treatment. We derive explicit results for the one-loop correction from the graviton self-energy induced by a massless, minimally coupled scalar.
96425170
Structure formation in a nonlocally modified gravity model
We study a nonlocally modified gravity model proposed by Deser and Woodard which gives an explanation for current cosmic acceleration. By deriving and solving the equations governing the evolution of the structure in the Universe, we show that this model predicts a pattern of growth that differs from standard general relativity (+dark energy) at the 10-30% level. These differences will be easily probed by the next generation of galaxy surveys, so the model should be tested shortly.
119164286
Exact 4-point scattering amplitude of the superconformal Schrödinger Chern-Simons theory
We consider the non-relativistic superconformal U(N) × U(N) Chern-Simons theory with level (k,−k) possessing fourteen supersymmetries. We obtain an exact four-point scattering amplitude of the theory to all orders in 1/N and 1/k and prove that the scattering amplitude becomes trivial when k = 1 and 2. We confirm this amplitude to one-loop order by using an explicit field theoretic computation and show that the beta function for the contact interaction vanishes to the one-loop order, which is consistent with the quantum conformal invariance of the underlying theory.
119251409
Nonlocal Gravity and Structure in the Universe
The observed acceleration of the Universe can be explained by modifying general relativity. One such attempt is the nonlocal model of Deser and Woodard. Here we fix the background cosmology using results from the Planck satellite and examine the predictions of nonlocal gravity for the evolution of structure in the Universe, confronting the model with three tests: gravitational lensing, redshift space distortions, and an estimator of gravity ${E}_{G}$ that combines spectroscopic information with lensing. Current data favor general relativity (GR) over nonlocal gravity: fixing primordial cosmology with the best fit parameters from Planck leads to weak lensing results favoring GR by 6.8 sigma; redshift space distortions measurements of the growth rate preferring GR by 7.8 sigma; and the single measurement of ${E}_{G}$ favoring GR, but by less than 1 sigma. The significance holds up even after the parameters are allowed to vary within Planck limits. The larger lesson is that a successful modified gravity model will likely have to suppress the growth of structure compared to general relativity.
21452649
Scalar Contribution to the Graviton Self-Energy during Inflation
We use dimensional regularization to evaluate the one loop contribution to the graviton self-energy from a massless, minimally coupled scalar on a locally de Sitter background. For noncoincident points our result agrees with the stress tensor correlators obtained recently by Perez-Nadal, Roura, and Verdaguer. We absorb the ultraviolet divergences using the R{sup 2} and C{sup 2} counterterms first derived by 't Hooft and Veltman, and we take the D=4 limit of the finite remainder. The renormalized result is expressed as the sum of two transverse, fourth order differential operators acting on nonlocal, de Sitter invariant structure functions. In this form it can be used to quantum correct the linearized Einstein equations so that one can study how the inflationary production of infrared scalars affects the propagation of dynamical gravitons and the force of gravity.