118356571
Direct detection of dynamical dark matter
Dynamical dark matter (DDM) is an alternative framework for dark-matter physics in which the dark-matter candidate is an ensemble of constituent fields with differing masses, lifetimes, and cosmological abundances. In this framework, it is the balancing of these quantities against each other across the ensemble as a whole which ensures phenomenological viability. In this paper, we examine the prospects for the direct detection of a DDM ensemble. In particular, we study the constraints imposed by current limits from direct-detection experiments on the parameter space of DDM models, and we assess the prospects for detecting such an ensemble and distinguishing it from traditional dark-matter candidates on the basis of data from the next generation of direct-detection experiments. For concreteness, we focus primarily on the case in which elastic scattering via spin-independent interactions dominates the interaction rate between atomic nuclei and the constituent particles of the ensemble. We also briefly discuss the effects of modifying these assumptions.
119200596
From DAMA/LIBRA To Super-Kamiokande
We consider the prospects for probing low-mass dark matter with the Super-Kamiokande experiment. We show that upcoming analyses including fully-contained events with sensitivity to dark matter masses from 5 to 10 GeV can test the dark matter interpretation of the DAMA/LIBRA signal. We consider prospects of this analysis for two light dark matter candidates: neutralinos and WIMPless dark matter.
118386561
Local scale-dependent non-gaussian curvature perturbations at cubic order
We calculate non-Gaussianities in the bispectrum and trispectrum arising from the cubic term in the local expansion of the scalar curvature perturbation. We compute to three-loop order and for general momenta. A procedure for evaluating the leading behavior of the resulting loop-integrals is developed and discussed. Finally, we survey unique non-linear signals which could arise from the cubic term in the squeezed limit. In particular, it is shown that loop corrections can cause fNLsq. to change sign as the momentum scale is varied. There also exists a momentum limit where τNL < 0 can be realized.
119283275
Constraints on bosonic dark matter from observation of old neutron stars
Baryon interactions with bosonic dark matter are constrained by the potential for dark matter-rich neutron stars to collapse into black holes. We consider the effect of dark matter self-interactions and dark matter annihilation on these bounds, and treat the evolution of the black hole after formation. We show that, for non-annihilating dark matter, these bounds extend up to $m_X \sim 10^{5-7}$ GeV, depending on the strength of self-interactions. However, these bounds are completely unconstraining for annihilating bosonic dark matter with an annihilation cross-section of $ \gtrsim 10^{-38} {\rm cm^3 /s}$. Dark matter decay does not significantly affect these bounds. We thus show that bosonic dark matter accessible to near-future direct detection experiments must participate in an annihilation or self-interaction process to avoid black hole collapse constraints from very old neutron stars.
118483875
Gamma rays from bino-like dark matter in the MSSM
We consider regions of the parameter space of the Minimal Supersymmetric Standard Model (MSSM) with bino-like neutralino dark matter in which a large fraction of the total dark matter annihilation cross section in the present era arises from annihilation to final states with monoenergetic photons. The region of interest is characterized by light sleptons and heavy squarks. We find that it is possible for the branching fraction to final states with monoenergetic photons to be comparable to that for continuum photons, but in those cases the total cross section will be so small that it is unlikely to be observable. For models where dark matter annihilation may be observable in the present era, the branching fraction to final states with monoenergetic photons is O(1-10%).
17960822
Raiders of the lost AdS
We demonstrate that under certain conditions a theory of conformal quantum mechanics will exhibit the symmetries of two half-Virasoro algebras. We further demonstrate the conditions under which these algebras combine to form a single-Virasoro algebra, and comment on the connection between this result and the AdS2/CFT1 correspondence.
120729664
A Class of Well Behaved Charged Analogues of Schwarzchild’s Interior Solution
A class of well behaved charged analogues of Schwarzchild’s interior solution has been obtained using a particular electric intensity. The solutions of this class are utilized to depict a superdense star model with surface density 2×1014 g cm−3. The solution obtained is new and the pressure (p), density (c2ρ), velocity of sound $(\sqrt{( dp / c^{2}d\rho )} )$ and (p/(c2ρ)) are monotonically decreasing towards the pressure free interface. Moreover the adiabatic constant is found to be more than (4/3) which is necessary for stability under radial perturbation. Also the electric intensity increases monotonically towards the surface. The well behaved model has the maximum mass M=1.740793MΘ, Radius 12.130308 km. The redshift at the center and on the surface is given by z0=0.384261 and za=0.292489. Out of the models of superdense star obtained couple of models represent Vela Pulsar for (i) α2=1.03, b=0.33, $\frac{a^{2}}{R^{2}} = 0.15$, Radius=10.8566 km, M=1.18331MΘ, I=0.642601×1045, (ii) α2=1.1, b=0.3, $\frac{a^{2}}{R^{2}} = 0.16$, Radius=11.197533 km, M=1.311438MΘ, I=0.774508×1045. All the solutions mentioned above are reducible to Schwarzchild interior solution in the absence of charge.