We study the thermodynamic parameters like entropy, energy etc. of a box of gas made up of indistinguishable particles when the box is kept in various static background spacetimes having a horizon. We compute the thermodynamic variables using both statistical mechanics as well as by solving the hydrodynamical equations for the system. When the box is far away from the horizon, the entropy of the gas depends on the volume of the box except for small corrections due to background geometry. As the box is moved closer to the horizon with one (leading) edge of the box at about Planck length ($L_p$) away from the horizon, the entropy shows an area dependence rather than a volume dependence. More precisely, it depends on a small volume $A_{\perp }{L}_p/2$ of the box, up to an order $\mathcal{O}(L_p/K{)}^2$ where $A_{\perp }$ is the transverse area of the box and $K$ is the (proper) longitudinal size of the box related to the distance between leading and trailing edge in the vertical direction (i.e. in the direction of the gravitational field). Thus the contribution to the entropy comes from only a fraction $\mathcal{O}(L_p/K)$ of the matter degrees of freedom and the rest are suppressed when the box approaches the horizon. Near the horizon all the thermodynamical quantities behave as though the box of gas has a volume $A_{\perp }{L}_p/2$ and is kept in a Minkowski spacetime. These effects are: (i) purely kinematic in their origin and are independent of the spacetime curvature (in the sense that the Rindler approximation of the metric near the horizon can reproduce the results) and (ii) observer dependent. When the equilibrium temperature of the gas is taken to be equal to the horizon temperature, we get the familiar $A_{\perp }/L_p^2$ dependence in the expression for entropy. All these results hold in a $D+1$ dimensional spherically symmetric spacetime. The analysis based on methods of statistical mechanics and the one based on thermodynamics applied to the gas treated as a fluid in static geometry, lead to the same results showing the consistency. The implications are discussed.

We show that it is possible to quantify the information content of a nonautonomous free field state in curved space-time. A covariance matrix is defined and it is shown that, for symmetric Gaussian field states, the matrix is connected to the entropy of the state. This connection is maintained throughout a quadratic nonautonomous (including possible phase transitions) evolution. Although particle-antiparticle correlations are dynamically generated, the evolution is isoentropic. If the current standard cosmological model for the inflationary period is correct, in absence of decoherence such correlations will be preserved, and could potentially lead to observable effects, allowing for a test of the model.

This work proposes a neutrino mass model that is derived using the minimal seesaw mechanism, which contains only two right-handed neutrinos, under the non-Abelian discrete flavor symmetry ${\mathbb{S}}_4\otimes {\mathbb{Z}}_2$. Two standard model doublets, $L_{\mu }$ and $L_{\tau }$, are assigned simultaneously to a $\mathbf{2}$ representation of ${\mathbb{S}}_4$. When the scalar fields introduced in this model, in addition to the standard model Higgs, and the leptons are coupled within the symmetry, the seesaw mechanism results in the tribimaximal neutrino mixing. This study examined the possible deviations from tribimaximal mixing related to the experimental data.

We study an improved AdS/QCD model at finite temperature and chemical potential. An ansatz for the $\beta$ function for the boundary theory allows for the derivation of a charged dilatonic black hole in bulk. The solution is asymptotically Reissner-Nordström-${\mathrm{AdS}}_5$ in the UV and ${\mathrm{AdS}}_2\times {\mathbb{R}}^3$ in the IR. We discuss the thermodynamical aspects of the solution. The fermionic susceptibilities are shown to deviate from the free fermionic limits at asymptotic temperatures despite the asymptotically free nature of the gauge coupling at the boundary. The Polyakov line and the temporal and spatial string tension dependence on both temperature and chemical potential are also discussed.

We report the results of a study of the exclusive charmless semileptonic decays, $B^{+}\to {\eta }^{(\prime )}{\ell }^{+}\nu$ and $B^0\to {\pi }^{-}{\ell }^{+}\nu$, undertaken with approximately $464\times {10}^6$ $B\overline{B}$ pairs collected at the ${\rm Y}(4S)$ resonance with the BABAR detector. The analysis uses events in which the signal $B$ decays are reconstructed with a loose neutrino reconstruction technique. We obtain partial branching fractions for $B^{+}\to \eta {\ell }^{+}\nu$ and $B^0\to {\pi }^{-}{\ell }^{+}\nu$ decays in three and 12 bins of $q^2$, respectively, from which we extract the $f_{+}(q^2)$ form-factor shapes and the total branching fractions $\mathcal{B}(B^{+}\to \eta {\ell }^{+}\nu )=(0.36\pm {0.05}_{\mathrm{stat}}\pm {0.04}_{\mathrm{syst}})\times {10}^{-4}$ and $\mathcal{B}(B^0\to {\pi }^{-}{\ell }^{+}\nu )=(1.42\pm {0.05}_{\mathrm{stat}}\pm {0.07}_{\mathrm{syst}})\times {10}^{-4}$. We also measure $\mathcal{B}(B^{+}\to {\eta }^{\prime }{\ell }^{+}\nu )=(0.24\pm {0.08}_{\mathrm{stat}}\pm {0.03}_{\mathrm{syst}})\times {10}^{-4}$. We obtain values for the magnitude of the CKM matrix element $|V_{ub}|$ using three different QCD calculations.

The results of the third phase of the Super-Kamiokande solar neutrino measurement are presented and compared to the first and second phase results. With improved detector calibrations, a full detector simulation, and improved analysis methods, the systematic uncertainty on the total neutrino flux is estimated to be $\pm 2.1\%$, which is about two thirds of the systematic uncertainty for the first phase of Super-Kamiokande. The observed ${}^8\mathrm{B}$ solar flux in the 5.0 to 20 MeV total electron energy region is $2.32\pm 0.04(\mathrm{stat})\pm 0.05(\mathrm{sys})\times {10}^6{\mathrm{cm}}^{-2}{\sec }^{-1}$ under the assumption of pure electron-flavor content, in agreement with previous measurements. A combined oscillation analysis is carried out using SK-I, II, and III data, and the results are also combined with the results of other solar neutrino experiments. The best-fit oscillation parameters are obtained to be ${sin}^2{\theta }_{12}={0.30}_{-0.01}^{+0.02}({tan}^2{\theta }_{12}={0.42}_{-0.02}^{+0.04})$ and $\Delta m_{21}^2={6.2}_{-1.9}^{+1.1}\times {10}^{-5}{\mathrm{eV}}^2$. Combined with KamLAND results, the best-fit oscillation parameters are found to be ${sin}^2{\theta }_{12}=0.31\pm 0.01({tan}^2{\theta }_{12}=0.44\pm 0.03)$ and $\Delta m_{21}^2=7.6\pm 0.2\times {10}^{-5}{\mathrm{eV}}^2$. The ${}^8\mathrm{B}$ neutrino flux obtained from global solar neutrino experiments is $5.3\pm 0.2(\mathrm{stat}+\mathrm{sys})\times {10}^6{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$, while the ${}^8\mathrm{B}$ flux becomes $5.1\pm 0.1(\mathrm{stat}+\mathrm{sys})\times {10}^6{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$ by adding KamLAND results. In a three-flavor analysis combining all solar neutrino experiments, the upper limit of ${sin}^2{\theta }_{13}$ is 0.060 at 95% C.L.. After combination with KamLAND results, the upper limit of ${sin}^2{\theta }_{13}$ is found to be 0.059 at 95% C.L.

Some time ago, Thies et al. showed that the Gross-Neveu model with a bare mass term possesses a kink-antikink crystalline phase. Corresponding self-consistent solutions, known earlier in polymer physics, are described by a self-isospectral pair of one-gap periodic Lamé potentials with a Darboux displacement depending on the bare mass. We study an unusual supersymmetry of such a second-order Lamé system, and show that the associated first-order Bogoliubov-de Gennes Hamiltonian possesses its own nonlinear supersymmetry. The Witten index is ascertained to be zero for both of the related exotic supersymmetric structures, each of which admits several alternatives for the choice of a grading operator. A restoration of the discrete chiral symmetry at zero value of the bare mass, when the kink-antikink crystalline condensate transforms into the kink crystal, is shown to be accompanied by structural changes in both of the supersymmetries. We find that the infinite period limit may or may not change the index. We also explain the origin of the Darboux-dressing phenomenon recently observed in a nonperiodic self-isospectral one-gap Pöschl-Teller system, which describes the Dashen, Hasslacher, and Neveu kink-antikink baryons.

In this work we build a gauge model based on the $SU(3{)}_c\otimes SU(3{)}_L\otimes U(1{)}_N$ symmetry with heavy neutrinos and show that we can have two weakly interacting cold dark matter candidates in its spectrum. This is achieved by noticing that a global $U(1)$ symmetry can be imposed on the model in such a way that the stability of the dark matter is guaranteed. We obtain their relic abundance and analyze their compatibility with recent direct detection experiments, also exploring the possibility of explaining the two events reported by CDMSII. An interesting outcome of this 3-3-1 model, concerning direct detection of these WIMPs, is a strong bound on the symmetry breaking scale, which imposes it to be above 3 TeV.

With a purpose of constructing a robust evolution system against numerical instability for integrating the Einstein equations, we propose a new formulation by adjusting the ADM evolution equations with constraints. We apply an adjusting method proposed by Fiske (2004) which uses the norm of the constraints, $C^2$. One of the advantages of this method is that the effective signature of adjusted terms (Lagrange multipliers) for constraint-damping evolution is predetermined. We demonstrate this fact by showing the eigenvalues of constraint propagation equations. We also perform numerical tests of this adjusted evolution system using polarized Gowdy-wave propagation, which show robust evolutions against the violation of the constraints than that of the standard ADM formulation.

We investigate damping and growth times of the quadrupolar $f$ mode for rapidly rotating stars and a variety of different polytropic equations of state in the Cowling approximation. This is the first study of the damping/growth time of these types of oscillations for fast-rotating neutron stars in a relativistic treatment where the spacetime degrees of freedom of the perturbations are neglected. We use these frequencies and damping/growth times to create robust empirical formulae which can be used for gravitational-wave asteroseismology. The estimation of the damping/growth time is based on the quadrupole formula and our results agree very well with Newtonian ones in the appropriate limit.

We have investigated effects of the QCD phase transition on the relic GW spectrum applying several equations of state for the strongly interacting matter: Besides the bag model, which describes a first-order transition, we use recent data from lattice calculations featuring a crossover. Finally, we include a short period of inflation during the transition which allows for a first-order phase transition at finite baryon density. Our results show that the QCD transition imprints a step into the spectrum of GWs. Within the first two scenarios, entropy conservation leads to a step-size determined by the relativistic degrees of freedom before and after the transition. The inflation of the third scenario much stronger attenuates the high frequency modes: An inflationary model being consistent with observation entails suppression of the spectral energy density by a factor of $\lesssim {10}^{-12}$.

We analyze the adjoint field inflation in supersymmetric (SUSY) $SU(5)$ model. In minimal SUSY $SU(5)$ hybrid inflation monopoles are produced at the end of inflation. We therefore explore the nonminimal model of inflation based on SUSY $SU(5)$, like shifted hybrid inflation, which provides a natural solution for the monopole problem. We find that the supergravity corrections with nonminimal Kähler potential are crucial to realize the central value of the scalar spectral index $n_s\simeq 0.96$ consistent with the 7 yr WMAP data. The tensor to scalar ratio $r$ is quite small, taking on values $r\lesssim {10}^{-5}$. Because of $R$ symmetry massless $SU(3)$ octet and $SU(2)$ triplet supermultiplets are present and could spoil gauge coupling unification. To keep gauge coupling unification intact, light vectorlike particles are added which are expected to be observed at LHC.

We explore a nuclear physics resolution to the discrepancy between the predicted standard big-bang nucleosynthesis (BBN) abundance of ${}^7\mathrm{Li}$ and its observational determination in metal-poor stars. The theoretical ${}^7\mathrm{Li}$ abundance is 3–4 times greater than the observational values, assuming the baryon-to-photon ratio, ${\eta }_{\mathrm{wmap}}$, determined by WMAP. The ${}^7\mathrm{Li}$ problem could be resolved within the standard BBN picture if additional destruction of $A=7$ isotopes occurs due to new nuclear reaction channels or upward corrections to existing channels. This could be achieved via missed resonant nuclear reactions, which is the possibility we consider here. We find some potential candidate resonances which can solve the lithium problem and specify their required resonant energies and widths. For example, a $1^{-}$ or $2^{-}$ excited state of ${}^{10}\mathrm{C}$ sitting at approximately 15.0 MeV above its ground state with an effective width of order 10 keV could resolve the ${}^7\mathrm{Li}$ problem; the existence of this excited state needs experimental verification. Other examples using known states include ${}^7\mathrm{Be}+t\to {}^{10}\mathrm{B}(18.80\mathrm{MeV})$, and ${}^7\mathrm{Be}+d\to {}^9\mathrm{B}(16.71\mathrm{MeV})$. For all of these states, a large channel radius ($a>10\mathrm{fm}$) is needed to give sufficiently large widths. Experimental determination of these reaction strengths is needed to rule out or confirm these nuclear physics solutions to the lithium problem.

The strongest bounds on some forms of Lorentz and $CPT$ violation come from astrophysical data, and placing such bounds may require understanding and modeling distant sources of radiation. However, it is also desirable to have bounds that do not rely on these kinds of detailed models. Bounds that do not rely on any modeling of astrophysical objects may be derived both from laboratory experiments and certain kinds of astrophysical observations. The strongest such bounds on isotropic modifications of electron, positron, and photon dispersion relations of the form $E^2=p^2+m^2+ϵp^3$ come from data on cosmological birefringence, the absence of photon decay, and radiation from lepton beams. The bounds range in strength from the $4\times {10}^{-13}$ to $6\times {10}^{-33}(\mathrm{GeV}{)}^{-1}$ levels.

The vacuum stability bounds on flavor-violating trilinear soft terms are revisited from the viewpoint that one should not ban a standard-model–like false vacuum as long as it is long-lived on a cosmological time scale. The vacuum transition rate is evaluated numerically by searching for the bounce configuration. Like stability, a metastability bound does not decouple even if sfermion masses grow. Apart from being more generous than stability, the new bounds are largely independent of Yukawa couplings except for the stop trilinears. With vacuum longevity imposed on otherwise arbitrary $LR$ insertions, it is found that a super flavor factory has the potential to probe sparticle masses up to a few TeV through $B$ and $\tau$ physics whereas the MEG experiment might cover a far wider range. In the stop sector, metastability is more restrictive than any existing experimental constraint such as from electroweak precision data. Also discussed are dependency on other parameters and reliability under radiative corrections.

We investigate the phenomenology of the Higgs sector of the minimal $B-L$ extension of the standard model. We present results for both the foreseen energy stages of the Large Hadron Collider ($\sqrt{s}=7$ and 14 TeV). We show that in such a scenario several novel production and decay channels involving the two physical Higgs states could be accessed at such a machine. Amongst these, several Higgs signatures have very distinctive features with respect to those of other models with an enlarged Higgs sector, as they involve interactions of Higgs bosons between themselves, with $Z^{\prime }$ bosons as well as with heavy neutrinos.

We discuss the deconstructed version of a topcolor-assisted technicolor model wherein the mechanism of top quark mass generation is separated from the rest of electroweak symmetry breaking. The minimal deconstructed version of this scenario is a “triangle moose” model, where the top quark gets its mass from coupling to a top-Higgs field, while the gauge boson masses are generated from a Higgsless sector. The spectrum of the model includes scalar (top-Higgs) and pseudoscalar (top-pion) states. In this paper, we study the properties of these particles, discuss their production mechanisms and decay modes, and suggest how best to search for them at the LHC.

We study the Landau gauge gluon and ghost propagators of $SU(3)$ gauge theory, employing the logarithmic definition for the lattice gluon fields and implementing the corresponding form of the Faddeev-Popov matrix. This is necessary in order to consistently compare lattice data for the bare propagators with that of higher-loop numerical stochastic perturbation theory. In this paper we provide such a comparison, and introduce what is needed for an efficient lattice study. When comparing our data for the logarithmic definition to that of the standard lattice Landau gauge we clearly see the propagators to be multiplicatively related. The data of the associated ghost-gluon coupling matches up almost completely. For the explored lattice spacings and sizes discretization artifacts, finite size, and Gribov-copy effects are small. At weak coupling and large momentum, the bare propagators and the ghost-gluon coupling are seen to be approached by those of higher-order numerical stochastic perturbation theory.

Using a custom 3-Čerenkov ring fitter, we report cross sections for ${\nu }_{\mu }$-induced charged-current single ${\pi }^0$ production on mineral oil (${\mathrm{CH}}_2$) from a sample of 5810 candidate events with 57% signal purity over an energy range of 0.5–2.0 GeV. This includes measurements of the absolute total cross section as a function of neutrino energy, and flux-averaged differential cross sections measured in terms of $Q^2$, ${\mu }^{-}$ kinematics, and ${\pi }^0$ kinematics. The sample yields a flux-averaged total cross section of $(9.2\pm {0.3}_{\mathrm{stat}}\pm {1.5}_{\mathrm{syst}})\times {10}^{-39}{\mathrm{cm}}^2/{\mathrm{CH}}_2$ at mean neutrino energy of 0.965 GeV.