Quantum cosmology is studied within the framework of the minimal quantum gravity theory proposed by Hořava. For this purpose we choose the Kantowski-Sachs (KS) model and construct the corresponding Wheeler-DeWitt equation. We study the solution to this equation in the ultraviolet limit for different values of the running parameter $\lambda$ of the theory. It is observed that the wave packet for this Universe changes completely compared with the one observed in the infrared (general relativity) regime. We also look at the classical solutions by means of a WKB semiclassical approximation. It is observed that if $\lambda$ takes its relativistic value $\lambda =1$ a generalized KS metric is obtained, which differs from the usual KS solution in general relativity by an additional term arising from the higher-order curvature terms in the action and which dominates the behavior of the solution for very small values of the time parameter. We discuss the physical properties of this solution by comparing it with the usual KS solution in general relativity. The resulting solution has no horizons but singularities.

We present a parametrized study of the effects of free thermal neutron injection on primordial nucleosynthesis, where both the rate and the time scale of injection are varied. This generic approach is found to yield a successful solution for reducing the ${}^7\mathrm{Li}$ abundance without causing significant problems to other elemental abundances. Our analysis demonstrates that hadronic injection, possibly due to decays or annihilations of dark matter particles with a mass of about 1 to 30 GeV, provides a possible solution to an outstanding problem in the standard big bang model.

We construct and discuss a toy model of the population of numerous nonidentical extragalactic sources of ultrahigh-energy cosmic rays. In the model, cosmic-ray particles are accelerated in magnetospheres of supermassive black holes in galactic nuclei, the key parameter of acceleration being the black-hole mass. We use astrophysical data on the redshift-dependent black-hole mass function to describe the population of these cosmic-ray accelerators, from weak to powerful, and confront the model with cosmic-ray data.

We place new constraints on the contribution of blazars to the large-scale isotropic gamma-ray background (IGRB) by jointly analyzing the measured source count distribution ($\log N$-$\log S$) of blazars and the measured intensity and anisotropy of the IGRB. We find that these measurements point to a consistent scenario in which unresolved blazars make $\lesssim 20\%$ of the IGRB intensity at 1–10 GeV while accounting for the majority of the measured anisotropy in that energy band. These results indicate that the remaining fraction of the IGRB intensity is made by a component with a low level of intrinsic anisotropy. We determine upper limits on the anisotropy from nonblazar sources, adopting the best-fit parameters of the measured source count distribution to calculate the unresolved blazar anisotropy. In addition, we show that the anisotropy measurement excludes some recently proposed models of the unresolved blazar population.

A new upper limit on the amplitude of primordial magnetic field (PMF) is derived by a comparison between a calculation of elemental abundances in big bang nucleosynthesis model and the latest observational constraints on the abundances. Updated nuclear reaction rates are adopted in the calculation. Effects of PMF on the abundances are consistently taken into account in the numerical calculation with the precise formulation of changes in physical variables. We find that abundances of ${}^3\mathrm{He}$ and ${}^6\mathrm{Li}$ increase while that of ${}^7\mathrm{Li}$ decreases when the PMF amplitude increases, in the case of the baryon-to-photon ratio determined from the measurement of cosmic microwave background radiation. We derive a constraint on the present amplitude of PMF, i.e., $B(0)<1.5\mu \mathrm{G}$ [corresponding to the amplitude less than $2.0\times {10}^{11}\mathrm{G}$ at big bang nucleosynthesis temperature of $T={10}^9\mathrm{K}$], based on the rigorous calculation.

We present a Newtonian multifluid formalism for superfluid neutron star cores, focusing on the additional dissipative terms which arise when one takes into account the individual dynamical degrees of freedom associated with the coupled “fluids.” The problem is of direct astrophysical interest as the nature of the dissipative terms can have significant impact on the damping of the various oscillation modes of the star and the associated gravitational-wave signatures. A particularly interesting application concerns the gravitational-wave driven instability of $f$- and $r$-modes. We apply the developed formalism to two specific three-fluid systems: (i) a hyperon core in which both $\Lambda$ and ${\Sigma }^{-}$ hyperons are present and (ii) a core of deconfined quarks in the color-flavor-locked phase in which a population of neutral $K^0$ kaons is present. The formalism is, however, general and can be applied to other problems in neutron-star dynamics (such as the effect of thermal excitations close to the superfluid transition temperature) as well as laboratory multifluid systems.

We propose a modified configuration of an advanced gravitational-wave detector that is a speed-meter-type interferometer with improved sensitivity with respect to quantum noise. With the addition of polarization-controlling components to the output of an arm cavity Michelson interferometer, an orthogonal polarization state of the interferometer can be used to store signal, returning it later with opposite phase to cancel position information below the storage bandwidth of the opposite mode. This modification provides an alternative to an external kilometer-scale Fabry-Pérot cavity, as presented in earlier work of Purdue and Chen [Phys. Rev. D 66, 122004 (2002)]. The new configuration requires significantly less physical infrastructure to achieve speed meter operation. The quantity of length and alignment degrees of freedom is also reduced. We present theoretical calculations to show that such a speed meter detector is capable of beating the strain sensitivity imposed by the standard quantum limit over a broad range of frequencies for Advanced Laser Interferometer Gravitational-wave Observatory-like parameters. The benefits and possible difficulties of implementing such a scheme are outlined. We also present results for tuning of the speed meter by adjusting the degree of polarization coupling, a novel possibility that does not exist in previously proposed designs, showing that there is a smooth transition from speed meter operation to that of a signal-recycling Michelson behavior.

We establish a relation between certain classes of flux compactifications and certain families of black hole microstate solutions. This connection reveals a rather unexpected result: there exist supersymmetric solutions of $N=8$ supergravity that live inside many $N=2$ truncations, but are not supersymmetric inside any of them. If this phenomenon is generic, it indicates the possible existence of much larger families of supersymmetric black rings and black hole microstates than previously thought.

Within the recently proposed ghost-free bigravity theory, we present the most general cosmological solution for which the physical metric is homogeneous and isotropic, while the second metric is inhomogeneous. The solution includes a matter source and exists for generic values of the theory parameters. The physical metric describes a universe with an effective cosmological term mimicked by the graviton mass, which causes the late time acceleration. When perturbed, this universe should rest approximately homogeneous and isotropic in space regions small compared to the graviton Compton length. In the limit where the massless graviton decouples, the solution fulfills the equations of the ghost-free massive gravity.

We propose homogeneous metrics of Petrov type III that describe gyrating Schrödinger geometries as duals to some nonrelativistic field theories, in which the Schrödinger symmetry is broken further so that the phase space has a linear dependence of the momentum in a selected direction. We show that such solutions can arise in four-dimensional Einstein-Weyl supergravity as well as higher-dimensional extended gravities with quadratic curvature terms coupled to a massive vector. In Einstein-Weyl supergravity, the gyrating Schrödinger solutions can be supersymmetric, preserving $\frac{1}{4}$ of the supersymmetry. We obtain the exact Green function in the phase space associated with a bulk free massive scalar.

Preheating and other particle production phenomena in the early Universe can give rise to high-energy out-of-equilibrium fermions with an anisotropic stress. We develop a formalism to calculate the spectrum of gravitational waves due to fermions, and apply it to a variety of scenarios after inflation. We pay particular attention to regularization issues. We show that fermion production sources a stochastic background of gravitational waves with a significant amplitude, but we find that typical frequencies oef this new background are not within the presently accessible direct detection range. However, small-coupling scenarios might still produce a signal observable by planned detectors, and thus open a new window into the physics of the very early Universe.

We list all scalar and vector leptoquark states that contribute to the $b\to s{\ell }^{+}{\ell }^{-}$ effective Hamiltonian. There are altogether three scalar and four vector leptoquarks that are relevant. For contribution of each state we infer the correlations between effective operators and find that only two baryon number-violating vector leptoquarks give rise to scalar and pseudoscalar four-fermion operators, whereas the scalar states can contribute to those operators only when two states with same charge are present. We bound the resulting Wilson coefficients by imposing experimental constraints coming from branching fractions of $B\to K{\ell }^{+}{\ell }^{-}$, $B_s\to {\mu }^{+}{\mu }^{-}$, and $B\to X_s{\mu }^{+}{\mu }^{-}$ decays.

The extension of the standard model to $SU(3{)}_L\times SU(3{)}_R\times SU(3{)}_C$ is considered. Spontaneous symmetry breaking requires two Higgs field multiplets with a strong hierarchical structure of vacuum expectation values. These vacuum expectation values, some of them known from experiment, are used to construct invariant potentials in the form of a sum of individual potentials relevant at the weak scale. As in a previous suggestion one may normalize the most important individual potentials such that their mass eigenvalues agree with their very large vacuum expectation values. In this case (for a wide class of parameters) the scalar field corresponding to the standard model Higgs turns out to have the precise mass value $m_{\mathrm{Higgs}}=\frac{v}{\sqrt{2}}=123\mathrm{GeV}$ at the weak scale. The physical mass (pole mass) is larger and found to be $125\pm 1.4\mathrm{GeV}$.

The transverse profile of the chromoelectric flux tubes in SU(2) and SU(3) pure gauge theories is analyzed by a simple variational ansatz using a strict analogy with ordinary superconductivity. Our method allows to extract the penetration length and the coherence length of the flux tube.

We calculate inclusive hadrons production in $pA$ collisions in the small-$x$ saturation formalism at one-loop order. The differential cross section is written into a factorization form in the coordinate space at the next-to-leading order, while the naive form of the convolution in the transverse momentum space does not hold. The rapidity divergence with small-$x$ dipole gluon distribution of the nucleus is factorized into the energy evolution of the dipole gluon distribution function, which is known as the Balitsky-Kovchegov equation. Furthermore, the collinear divergences associated with the incoming parton distribution of the nucleon and the outgoing fragmentation function of the final state hadron are factorized into the splittings of the associated parton distribution and fragmentation functions, which allows us to reproduce the well-known Dokshitzer-Gribov-Lipatov-Altarelli-Parisi equation. The hard coefficient function, which is finite and free of divergence of any kind, is evaluated at one-loop order.

Studying the substructure of jets has become a powerful tool for event discrimination and for studying QCD. Typically, jet substructure studies rely on Monte Carlo simulation for vetting their usefulness; however, when possible, it is also important to compute observables with analytic methods. Here, we present a global next-to-leading-log resummation of the angular correlation function which measures the contribution to the mass of a jet from constituents that are within an angle $R$ with respect to one another. For a scale-invariant jet, the angular correlation function should scale as a power of $R$. Deviations from this behavior can be traced to the breaking of scale invariance in QCD. To do the resummation, we use soft-collinear effective theory relying on the recent proof of factorization of jet observables at $e^{+}{e}^{-}$ colliders. Nontrivial requirements of factorization of the angular correlation function are discussed. The calculation is compared to the Monte Carlo parton shower and next-to-leading order results. The different calculations are important in distinct phase space regions and exhibit that jets in QCD are, to very good approximation, scale invariant over a wide dynamical range.

Color octet resonances arise in many well motivated theories beyond the Standard Model. As colored objects they are produced copiously at the LHC and can be discovered in early searches for new physics in dijet final states. Once they are discovered it will be important to measure the couplings of the new resonances to determine the underlying theoretical structure. We propose a new channel, the associated production of $W$, $Z$ gauge bosons and color octet resonances, to help determine the chiral structure of the couplings. We present our analysis for a range of color octet masses (2.5 to 4.5 TeV), couplings and decay widths for the LHC with center of mass energy of 14 TeV and $10{\mathrm{fb}}^{-1}$ or $100{\mathrm{fb}}^{-1}$ of integrated luminosity. We find that the LHC can probe a large region of the parameter space up to very small couplings.

New data are reported from the operation of a 4.0-kg ${\mathrm{CF}}_3\mathrm{I}$ bubble chamber in the 6800-foot-deep SNOLAB underground laboratory. The effectiveness of ultrasound analysis in discriminating alpha-decay background events from single nuclear recoils has been confirmed, with a lower bound of $>99.3\%$ rejection of alpha-decay events. Twenty single nuclear recoil event candidates and three multiple bubble events were observed during a total exposure of 553 kg-days distributed over three different bubble nucleation thresholds. The effective exposure for single bubble recoil-like events was 437.4 kg-days. A neutron background internal to the apparatus, of known origin, is estimated to account for five single nuclear recoil events and is consistent with the observed rate of multiple bubble events. The remaining excess of single bubble events exhibits characteristics indicating the presence of an additional background. These data provide new direct detection constraints on WIMP-proton spin-dependent scattering for WIMP masses $>20\mathrm{GeV}/{\mathrm{c}}^2$ and demonstrate significant sensitivity for spin-independent interactions.

Measurements of the differential cross section and the transverse single-spin asymmetry, $A_N$, vs $x_F$ for ${\pi }^0$ and $\eta$ mesons are reported for $0.4<x_F<0.75$ at an average pseudorapidity of 3.68. A data sample of approximately $6.3{\mathrm{pb}}^{-1}$ was analyzed, which was recorded during $p^{\uparrow }+p$ collisions at $\sqrt{s}=200\mathrm{GeV}$ by the STAR experiment at RHIC. The average transverse beam polarization was 56%. The cross section for ${\pi }^0$, including the previously unmeasured region of $x_F>0.55$, is consistent with a perturbative QCD prediction, and the $\eta /{\pi }^0$ cross-section ratio agrees with existing midrapidity measurements. For $0.55<x_F<0.75$, the average $A_N$ for $\eta$ is $0.210\pm 0.056$, and that for ${\pi }^0$ is $0.081\pm 0.016$. The probability that these two asymmetries are equal is $\sim 3\%$.

For supersymmetric solutions of $D3\mathrm{\text{−}}(M2\mathrm{\text{−}})$ branes with ${\mathrm{AdS}}_3({\mathrm{AdS}}_2)$ factor, it is known that the internal space is expressible as $U(1)$ fibration over Kähler space which satisfies a specific partial differential equation involving the Ricci tensor. In this paper we study the wrapped brane solutions of $D3$- and $M2$-branes, which were originally constructed using gauged supergravity and uplifted to $D=10$ and $D=11$. We rewrite the solutions in canonical form, identify the backreacted Kähler geometry, and present a class of solutions which satisfy the Killing spinor equation.