We extend our recent work on the quasilocal formulation of conserved charges to a theory of gravity containing a gravitational Chern-Simons term. As an application of our formulation, we compute the off-shell potential and quasilocal conserved charges of some black holes in three-dimensional topologically massive gravity. Our formulation for conserved charges reproduces very effectively the well-known expressions on conserved charges and the entropy expression of black holes in the topologically massive gravity.

Deconfined quark matter may exist in a crystalline color-superconducting phase in the interiors of compact stars. In this paper, we study the torsional oscillations of compact stars featuring a crystalline color-superconducting quark-matter core in general relativity. Depending on the size of the crystalline core and the value of the gap parameter $\Delta$, we find that the frequencies of the torsional oscillation modes can range from a few hundred hertz to a few kilohertz for our canonical $1.4M_{\odot }$ compact star models. We have also studied the prospect for detecting the gravitational-wave signals emitted from these modes in a pulsar glitch event. Assuming that at least 10% of the energy released in a Vela glitch can be channeled to the oscillation modes, we find that the Einstein Telescope should be able to detect these signals in quite general situations. Furthermore, if the size of the crystalline core is comparable to the stellar radius and the gap parameter is relatively small at $\Delta \sim 5\mathrm{MeV}$, the signal-to-noise ratio for Advanced LIGO could reach $\sim 10$ for a Vela glitch. Our optimistic results suggest that we might already be able to probe the nature of crystalline color-superconducting quark matter with the second-generation gravitational-wave detectors when they come online in the next few years.

The newly released Planck cosmic microwave background data place tight constraints on slow-roll inflationary models. Some commonly discussed inflationary potentials are disfavored due mainly to the large tensor-to-scalar ratio. In this paper we show that these potentials may be in good agreement with the Planck data when the inflaton has a nonminimal coupling to the Gauss-Bonnet term. Moreover, such a coupling violates the consistency relation between the tensor spectral index and tensor-to-scalar ratio. If the tensor spectral index is allowed to vary freely, the Planck constraints on the tensor-to-scalar ratio are slightly improved.

In the context of scalar-tensor theories we study the evolution of the density contrast for Jordan-Fierz-Brans-Dicke theories in a Friedmann-Lemaître-Robertson-Walker universe. Calculations are performed in the Einstein frame with the cosmological background described as $\Lambda$-cold dark matter ($\Lambda \mathrm{CDM}$) and supplemented by a Jordan-Fierz-Brans-Dicke field. By using a completely general procedure valid for all scalar-tensor theories, we obtain the exact fourth-order differential equation for the density contrast evolution in modes of arbitrary size. In the case of sub-Hubble modes, the expression reduces to a simpler but still fourth-order equation that is then compared with the standard (quasistatic) approximation. Differences with respect to the evolution as predicted by the standard concordance $\Lambda \mathrm{CDM}$ model are observed depending on the value of the coupling.

We study how many-body effects alter the dark matter (DM) thermalization time inside neutron stars. We find that Pauli blocking, kinematic constraints, and superfluidity and superconductivity in the neutron star significantly affect the DM thermalization time, in general lengthening it. This could change the final DM mass and DM-nucleon cross section constraints by considering black hole formation in neutron stars due to DM accretion. We consider the class of models in which DM is an asymmetric, complex scalar particle with a mass between 1 keV and 5 GeV, which couples to regular matter via some heavy vector boson. Interestingly, we find that the discovery of asymmetric, bosonic DM could motivate the existence of exotic neutron star cores. We apply our results to the case of mixed sneutrino DM.

In a homogeneous and isotropic universe bulk viscosity is the unique viscous effect that is capable of modifying the background dynamics. Effects like shear viscosity or heat conduction can only change the evolution of the perturbations. The existence of a bulk viscous pressure in a fluid—which in order to obey the second law of thermodynamics must be negative—reduces its effective pressure. We discuss the degeneracy in bulk viscous cosmologies and address the possibility that phantom dark energy cosmology could be caused by the existence of nonequilibrium pressure in any one of the cosmic components. We establish the conditions under which either viscous matter or radiation cosmologies can be mapped into the phantom dark energy scenario with constraints from multiple observational data sets.

We describe a simple model of chaotic inflation in supergravity where one can easily tune not only the basic cosmological parameters such as $n_s$, $r$, and $f_{NL}$ but also a possible (subdominant) cosmic string contribution to the cosmic microwave background anisotropy.

We investigate the linearly and quadratically coupled cubic Galileon models that include linear potentials. These models may explain the late-time acceleration. In these cases, we need two equations of state parameters named the native and effective equations of state to test whether the Universe is accelerating or not because there is coupling between the cold dark matter and Galileon. It turns out that there is no transition from the accelerating phase to the phantom phase in the future.

We consider implications of the IceCube signal for hadronuclear ($pp$) scenarios of neutrino sources such as galaxy clusters/groups and star-forming galaxies. Since the observed neutrino flux is comparable to the diffuse $\gamma$-ray background flux obtained by Fermi, we place new, strong upper limits on the source spectral index, $\Gamma \lesssim 2.1–2.2$. In addition, the new IceCube data imply that these sources contribute at least 30%–40% of the diffuse $\gamma$-ray background in the 100 GeV range and even $\sim 100\%$ for softer spectra. Our results, which are insensitive to details of the $pp$ source models, are one of the first strong examples of the multimessenger approach combining the measured neutrino and $\gamma$-ray fluxes. The $pp$ origin of the IceCube signal can further be tested by constraining $\Gamma$ with sub-PeV neutrino observations, by unveiling the sub-TeV diffuse $\gamma$-ray background and by observing such $pp$ sources with TeV $\gamma$-ray detectors. We also discuss specific $pp$ source models with a multi-PeV neutrino break/cutoff, which are consistent with the current IceCube data.

We propose a new mechanism for generating a $CP$ phase via a Higgs vacuum expectation value originating from geometry of an extra dimension. A twisted boundary condition is the key to produce an extra-dimension coordinate-dependent vacuum expectation value, which contains a $CP$ phase degree of freedom and can be a new source of a $CP$ phase in higher-dimensional gauge theories. As an illustrative example, we apply our mechanism to a five-dimensional gauge theory with point interactions and show that our mechanism can dynamically produce a nontrivial $CP$-violating phase with electroweak symmetry breaking, even though the five-dimensional model does not include any $CP$-violating phases of Yukawa couplings in the five-dimensional Lagrangian because of a single generation of five-dimensional fermions. We apply our mechanism to a model with point interactions, which has no source of $CP$-violating phases in the couplings of the higher-dimensional action, and show that a nontrivial $CP$ phase dynamically appears.

Many new physics models beyond the standard model, such as the littlest Higgs models and the left-right twin Higgs models, predict the existence of the large charged Higgs couplings $H^{-}q\overline{b}$ and $H^{+}b\overline{q}$, where $q=t$ or the new vectorlike heavy quark $T$. On the other hand, some new physics models, like the littlest Higgs, also predict the gauge-Higgs couplings. Such couplings may have rich collider phenomenology. We focus our attention on these couplings induced by the littlest Higgs models and the left-right twin Higgs models and consider their contributions to the production cross section for $W^{\pm }{H}^{\mp }$ production at the large hadron colliders. We find that the cross sections in the littlest Higgs models on the parton level $gg\to W^{\pm }{H}^{\mp }$ and $q\overline{q}\to W^{\pm }{H}^{\mp }$ ($q=u$, $d$, $s$, $c$, $b$) may reach tens of dozens femtobarns in reasonable parameter space at the collision energy of 14 TeV and that the total cross section can even reach a few hundred femtobarns in certain favored space. While in the left-right twin Higgs models, the production rates are basically one order lower than those in the littlest Higgs models. Therefore, due to the large cross sections of that in the littlest Higgs models, it may be possible to probe the charged Higgs via this process in a certain parameter space.

The Froggatt-Nielsen mechanism provides an elegant explanation for the hierarchies of fermion masses and mixings in terms of a $U(1)$ symmetry. Promoting such a family symmetry to an $R$ symmetry, we explicitly construct supersymmetric Froggatt-Nielsen models which are gauged, family-dependent $U(1{)}_R$ completions of the ${\mathbb{Z}}_4^R$ symmetry proposed by Lee, Raby, Ratz, Ross, Schieren, Schmidt-Hoberg and Vaudrevange in 2010. Forbidden by ${\mathbb{Z}}_4^R$, the $\mu$ term is generated around the supersymmetry breaking scale $m_{3/2}$ from either the Kähler potential or the superpotential. Neutrinos acquire their mass via the type-I seesaw mechanism with three right-handed neutrino superfields. Taking into account the Green-Schwarz anomaly cancellation conditions, we arrive at a total of $3\times 34$ distinct phenomenologically viable charge assignments for the standard model fields, most of which feature highly fractional charges.

The recent measurements of $B_s^0\to \mu \overline{\mu }$ decay candidates at the LHC consistent with the standard model rate and the improving upper limits for $B_d^0\to \mu \overline{\mu }$ can strongly constrain beyond the standard model physics. For example, in supersymmetric models with broken $R$-parity ($R\mathrm{pV}$), they restrict the size of the new couplings. We use the combination of the public software packages SARAH and SPheno to derive new bounds on several combinations of $R\mathrm{pV}$ couplings. We improve existing limits for the couplings which open tree-level decay channels and state new limits for combinations which induce loop contributions. This is the first study which performs a full one-loop analysis of these observables in the context of $R$-parity violation. It turns out that at one loop despite the strong experimental limits only combinations of $R$-parity violating couplings are constrained which include third generation fermions. We compare our limits with those obtained via $B\to X_s\gamma$ and discuss the differences.

We investigate the chiral properties of near-zero modes for thick classical center vortices in $SU(2)$ lattice gauge theory as examples of the phenomena which may arise in a vortex vacuum. In particular we analyze the creation of near-zero modes from would-be zero modes of various topological charge contributions from center vortices. We show that classical colorful spherical vortex and instanton ensembles have almost identical Dirac spectra and the low-lying eigenmodes from spherical vortices show all characteristic properties for chiral symmetry breaking. We further show that also vortex intersections are able to give rise to a finite density of near-zero modes, leading to chiral symmetry breaking via the Banks-Casher formula. We discuss the mechanism by which center vortex fluxes contribute to chiral symmetry breaking.

We investigate the chemical-potential ($\mu$) dependence of static-quark free energies in both the real and imaginary $\mu$ regions, performing lattice QCD simulations at imaginary $\mu$ and extrapolating the results to the real-$\mu$ region with analytic continuation. Lattice QCD calculations are done on a ${16}^3\times 4$ lattice with the clover-improved two-flavor Wilson fermion action and the renormalization-group-improved Iwasaki gauge action. Static-quark potentials are evaluated from the Polyakov-loop correlation functions in the deconfinement phase. To perform the analytic continuation, the potential calculated at imaginary $\mu =i{\mu }_{\mathrm{I}}$ is expanded into a Taylor expansion series of $i{\mu }_{\mathrm{I}}/T$ up to fourth order and the pure imaginary variable $i{\mu }_{\mathrm{I}}/T$ is replaced by the real one ${\mu }_{\mathrm{R}}/T$. At real $\mu$, the fourth-order term sizably weakens the $\mu$ dependence of the potential. At long distance, all of the color-singlet and -nonsinglet potentials tend to twice the single-quark free energy, indicating that the interactions between static quarks are fully color screened for finite $\mu$. For both real and imaginary $\mu$, the color-singlet $q\overline{q}$ and the color-antitriplet $qq$ interactions are attractive, whereas the color-octet $q\overline{q}$ and the color-sextet $qq$ interactions are repulsive. The attractive interactions have a stronger $\mu /T$ dependence than the repulsive interactions. The color-Debye screening mass is extracted from the color-singlet potential at imaginary $\mu$, and the mass is extrapolated to real $\mu$ by analytic continuation. The screening mass thus obtained has a stronger $\mu$ dependence than the prediction of hard-thermal-loop perturbation theory at both real and imaginary $\mu$.

We employ a chiral Lagrangian framework with three dynamical flavors to calculate the masses of the lowest-lying vector mesons to one-loop accuracy, and use the resulting formulas to extrapolate recent lattice data from the QCDSF Collaboration on vector meson masses and mass ratios to the physical point. Our representation for the vector meson self-energies also enables us to discuss loop corrections to the $\omega \varphi$ mixing amplitude.

The interaction-dependent part of the $x^2$ moment of the twist-3 polarized parton distribution $g_2(x)$ is related to the transverse force acting on the active quark in deep-inelastic scattering off a transversely polarized nucleon immediately after it has absorbed the virtual photon. Similarly, the $x^2$ moment of the chirally odd twist-3 unpolarized parton distribution $e(x)$ can be related to the transverse force experienced by a transversely polarized quark ejected from a transversely polarized nucleon.

We present improved upper and lower bounds for the momentum-space ghost propagator of Yang-Mills theories in terms of the two smallest nonzero eigenvalues (and their corresponding eigenvectors) of the Faddeev-Popov matrix. These results are verified using data from four-dimensional numerical simulations of SU(2) lattice gauge theory in minimal Landau gauge at $\beta =2.2$, for lattice sides $N=16$, 32, 48 and 64. Gribov-copy effects are discussed by considering four different sets of numerical minima. We then present a lower bound for the smallest nonzero eigenvalue of the Faddeev-Popov matrix in terms of the smallest nonzero momentum on the lattice and of a parameter characterizing the geometry of the first Gribov region $\Omega$. This allows a simple and intuitive description of the infinite-volume limit in the ghost sector. In particular, we show how nonperturbative effects may be quantified by the rate at which typical thermalized and gauge-fixed configurations approach the boundary of $\Omega$, known as the first Gribov horizon. As a result, a simple and concrete explanation emerges for why lattice studies do not observe an enhanced ghost propagator in the deep infrared limit. Most of the simulations have been performed on the Blue Gene/P–IBM supercomputer shared by Rice University and São Paulo University.

A study of nonstrange meson-baryon systems has been made with the idea of understanding the properties of the low-lying $1/2^{-}$ $N^{*}$ and $\Delta$ resonances. The coupled channels are built by considering the pseudoscalar and vector mesons together with the octet baryons. The formalism is based on obtaining the interactions from the lowest order chiral Lagrangian when dealing with pseudoscalar mesons and relying on the hidden local symmetry in the case of the vector mesons. The transition between the two systems is obtained by replacing the photon by a vector meson in the Kroll-Ruderman theorem for the photoproduction of pseudoscalar mesons. The subtraction constants, required to calculate the loop function in the scattering equations, are constrained by fitting the available experimental data on some of the reactions with pseudoscalar meson-baryon final states. As a consequence, we find resonances which can be related to $N^{*}(1535)$, $N^{*}(1650)$ (with a double pole structure), $N^{*}(1895)$, and $\Delta (1620)$. We conclude that these resonances can be interpreted, at least partly, as dynamically generated resonances and that the vector mesons play an important role in determining the dynamical origin of the low-lying $N^{*}$ and $\Delta$ states.