Thermodynamics of Schwarzschild-(Anti-)de Sitter Black Holes with account of quantum corrections

We discuss the quantum corrections to thermodynamics (and geometry) of S(A)dS BHs using large $N$ one-loop anomaly induced effective action for dilaton coupled matter (scalars and spinors). It is found the temperature, mass and entropy with account of quantum effects for multiply horizon SdS BH and SAdS BH what also gives the corresponding expressions for their limits: Schwarzschild and de Sitter spaces. In the last case one can talk about quantum correction to entropy of expanding Universe. The anomaly induced action under discussion corresponds to 4d formulation (s-wave approximation, 4d quantum matter is minimal one) as well as 2d formulation (complete effective action, 2d quantum matter is dilaton coupled one). Hence, most of results are given for the same gravitational background with interpretation as 4d quantum corrected BH or 2d quantum corrected dilatonic BH. Quantum aspects of thermodynamics of 4d 't Hooft BH model are also considered.Comment: LaTeX file, 28 pages, some misprints are correcte

Discovery of supersymmetry with degenerated mass spectrum

Discovery of supersymmetric (SUSY) particles at the Large Hadron Collider(LHC) has been studied for the models where squarks and gluino are much heavier than the lightest supersymetric particle (LSP). In this paper, we investigate the SUSY discovery in the models with degenerated mass spectrum up to m_LSP~0.7 m_sq. Such mass spectrum is predicted in certain parameter region of the mixed modulas anomaly mediation (MMAM) model. We find that the effective transverse mass of the signal for the degenerated parameters shows the distribution similar to that of the background. Experimental sensitivity of the SUSY particles at the LHC therefore depends on the uncertainty of the background in this class of model. We also find that SUSY signal shows an interesting correlation between M_eff and ETmiss which may be used to determine the signal region properly to enhance the S/N ratio even if the sparticle masses are rather degenerated. The structure is universal for the models with new heavy colored particles decaying into visible particles and a stable neutral particle, dark matter.Comment: 18 pages, 7 figure, revtex

Inhomogeneous Equation of State of the Universe: Phantom Era, Future Singularity and Crossing the Phantom Barrier

The dark energy universe equation of state (EOS) with inhomogeneous,Hubble parameter dependent term is considered. The motivation to introduce such a term comes from time-dependent viscosity considerations and modifications of general relativity. For several explicit examples of such EOS it is demonstrated how the type of future singularity changes, how the phantom epoch emerges and how crossing of phantom barrier occurs. Similar cosmological regimes are considered for the universe with two interacting fluids and for universe with implicit EOS. For instance, the crossing of phantom barrier is realized in easier way, thanks to the presence of inhomogeneous term. The thermodynamical dark energy model is presented where the universe entropy may be positive even at phantom era as a result of crossing of w=-1 barrier.Comment: LaTeX, 13 pages, refs. added, version to appear in PR

String versus Einstein frame in an AdS/CFT induced quantum dilatonic brane-world universe

AdS/CFT induced quantum dilatonic brane-world where 4d boundary is flat or de Sitter (inflationary) or Anti-de Sitter brane is considered. The classical brane tension is fixed but boundary QFT produces the effective brane tension via the account of corresponding conformal anomaly induced effective action. This results in inducing of brane-worlds in accordance with AdS/CFT set-up as warped compactification. The explicit, independent construction of quantum induced dilatonic brane-worlds in two frames: string and Einstein one is done. It is demonstrated their complete equivalency for all quantum cosmological brane-worlds under discussion, including several examples of classical brane-world black holes. This is different from quantum corrected 4d dilatonic gravity where de Sitter solution exists in Einstein but not in Jordan (string) frame. The role of quantum corrections on massive graviton perturbations around Anti-de Sitter brane is briefly discussed.Comment: LaTeX file, 24 pages, minor changes to match with published versio

Black hole solutions in F(R) gravity with conformal anomaly

In this paper, we consider $F(R)=R+f(R)$ theory instead of Einstein gravity with conformal anomaly and look for its analytical solutions. Depending on the free parameters, one may obtain both uncharged and charged solutions for some classes of $F(R)$ models. Calculation of Kretschmann scalar shows that there is a singularity located at $r=0$, which the geometry of uncharged (charged) solution is corresponding to the Schwarzschild (Reissner-Nordstr\"om) singularity. Further, we discuss the viability of our models in details. We show that these models can be stable depending on their parameters and in different epoches of the universe.Comment: 12 pages, one figur

Phantom phase power-law solution in f(G)f(G) gravity

Power-law solutions for $f(G)$ gravity coupled with perfect fluid have been studied for spatially flat universe. It is shown that despite the matter dominated and accelerating power-law solutions, the power-law solution exists for an special form of $f(G)$ when this universe enters a Phantom phase.Comment: 10 pages, Published online in Astrophysics and Space Scienc

Universal features of the holographic duality: conformal anomaly and brane gravity trapping from 5d AdS Black Hole

We calculate the holographic conformal anomaly and brane Newton potential when bulk is 5d AdS BH. It is shown that such anomaly is the same as in the case of pure AdS or (asymptotically) dS bulk spaces, i.e. it is (bulk) metric independent one. While Newton potential on the static brane in AdS BH is different from the one in pure AdS space, the gravity trapping still occurs for two branes system. This indicates to metric independence of gravity localization.Comment: LaTeX file, 14 page

Using Subsystem MT2 for Complete Mass Determinations in Decay Chains with Missing Energy at Hadron Colliders

We propose to use the MT2 concept to measure the masses of all particles in SUSY-like events with two unobservable, identical particles. To this end we generalize the usual notion of MT2 and define a new MT2(n,p,c) variable, which can be applied to various subsystem topologies, as well as the full event topology. We derive analytic formulas for its endpoint MT2{max}(n,p,c) as a function of the unknown test mass Mc of the final particle in the subchain and the transverse momentum pT due to radiation from the initial state. We show that the endpoint functions MT2{max}(n,p,c)(Mc,pT) may exhibit three different types of kinks and discuss the origin of each type. We prove that the subsystem MT2(n,p,c) variables by themselves already yield a sufficient number of measurements for a complete determination of the mass spectrum (including the overall mass scale). As an illustration, we consider the simple case of a decay chain with up to three heavy particles, X2 -> X1 -> X0, which is rather problematic for all other mass measurement methods. We propose three different MT2-based methods, each of which allows a complete determination of the masses of particles X0, X1 and X2. The first method only uses MT2(n,p,c) endpoint measurements at a single fixed value of the test mass Mc. In the second method the unknown mass spectrum is fitted to one or more endpoint functions MT2{max}(n,p,c)(Mc,pT) exhibiting a kink. The third method is hybrid, combining MT2 endpoints with measurements of kinematic edges in invariant mass distributions. As a practical application of our methods, we show that the dilepton W+W- and tt-bar samples at the Tevatron can be used for an independent determination of the masses of the top quark, the W boson and the neutrino, without any prior assumptions.Comment: 47 pages, 9 figures. revised version, published in JHEP. Major addition: a new appendix with the complete set of formulas for the MT2 endpoints as functions of the upstream transverse momentum pT and test mass M

Unifying inflation with dark energy in modified F(R) Horava-Lifshitz gravity

We study FRW cosmology for a non-linear modified F(R) Horava-Lifshitz gravity which has a viable convenient counterpart. A unified description of early-time inflation and late-time acceleration is possible in this theory, but the cosmological dynamic details are generically different from the ones of the convenient viable F(R) model. Remarkably, for some specific choice of parameters they do coincide. The emergence of finite-time future singularities is investigated in detail. It is shown that these singularities can be cured by adding an extra, higher-derivative term, which turns out to be qualitatively different when compared with the corresponding one of the convenient F(R) theory.Comment: LaTeX 12 pages, typos are correcte

Cosmological anti-deSitter space-times and time-dependent AdS/CFT correspondence

We study classes of five-dimensional cosmological solutions with negative curvature, which are obtained from static solutions by an exchange of a spatial and temporal coordinate, and in some cases by an analytic continuation. Such solutions provide a suitable laboratory to address the time-dependent AdS/CFT correspondence. For a specific example we address in detail the calculation of the boundary stress-energy and the Wilson line and find disagreement with the standard AdS/CFT correspondence. We trace these discrepancies to the time-dependent effects, such as particle creation, which we further study for specific backgrounds. We also identify specific time-dependent backgrounds that reproduce the correct conformal anomaly. For such backgrounds the calculation of the Wilson line in the adiabatic approximation indicates only a Coulomb repulsion.Comment: LaTeX file, 47 pages, discussion is extended, version to appear in PR