We consider the prospects for the detection of relatively light dark matter through direct annihilation to neutrinos. We specifically focus on the detection possibilities of water Cherenkov and liquid scintillator neutrino detection devices. We find, in particular, that liquid scintillator detectors may potentially provide excellent detection prospects for dark matter in the 4–10 GeV mass range. These experiments can provide excellent corroborative checks of the DAMA/LIBRA annual modulation signal, but may yield results for low mass dark matter in any case. We identify important tests of the ratio of electron to muon neutrino events (and neutrino versus antineutrino events), which discriminate against background atmospheric neutrinos. In addition, the fraction of events which arise from muon neutrinos or antineutrinos ($R_{\mu }$ and $R_{\overline{\mu }}$) can potentially yield information about the branching fractions of hypothetical dark matter annihilations into different neutrino flavors. These results apply to neutrinos from secondary and tertiary decays as well, but will suffer from decreased detectability.

A simple gauged linear sigma model with several parameters to take the symmetry breaking and the mass differences between the vector meson and the axial vector meson into account is considered here as a possibly useful “template” for the role of a light scalar in QCD as well as for (at a different scale) an effective Higgs sector for some recently proposed walking technicolor models. An analytic procedure is first developed for relating the Lagrangian parameters to four well established (in the QCD application) experimental inputs. One simple equation distinguishes three different cases: i. QCD with axial vector particle heavier than vector particle, ii. possible technicolor model with vector particle heavier than the axial vector one, iii. the unphysical QCD case where both the Kawarabayashi-Suzuki-Riazuddin-Fayazuddin and Weinberg relations hold. The model is applied to the $s$-wave pion-pion scattering in QCD. Both the near threshold region and (with an assumed unitarization) the “global” region up to about 800 MeV are considered. It is noted that there is a little tension between the choice of “bare” sigma mass parameter for describing these two regions. If a reasonable “global” fit is made, there is some loss of precision in the near threshold region.

A new method is described for constructing initial data for a binary neutron-star system in quasiequilibrium circular orbit. Two formulations for nonconformally flat data, waveless and near-zone helically symmetric, are introduced; in each formulation, the Einstein-Euler system, written in $3+1$ form on an asymptotically flat spacelike hypersurface, is exactly solved for all metric components, including the spatially nonconformally flat potentials, and for irrotational flow. A numerical method applicable to both formulations is explained with an emphasis on the imposition of a spatial gauge condition. Results are shown for solution sequences of irrotational binary neutron-stars with matter approximated by parametrized equations of state that use a few segments of polytropic equations of state. The binding energy and total angular momentum of solution sequences computed within the conformally flat—Isenberg-Wilson-Mathews—formulation are closer to those of the third post-Newtonian (3PN) two point particles up to the closest orbits, for the more compact stars, whereas sequences resulting from the waveless/near-zone helically symmetric formulations deviate from the 3PN curve even more for the sequences with larger compactness. We think it likely that this correction reflects an overestimation in the Isenberg-Wilson-Mathews formulation as well as in the 3PN formula, by $\sim 1$ cycle in the gravitational-wave phase during the last several orbits. The work suggests that imposing spatial conformal flatness results in an underestimate of the quadrupole deformation of the components of binary neutron-star systems in the last few orbits prior to merger.

We report our rederivation of the equations of motion for relativistic compact binaries through the third-and-a-half post-Newtonian (3.5 PN) order approximation to general relativity using the strong field point particle limit to describe self-gravitating stars instead of the Dirac delta functional. The computation is done in harmonic coordinates. Our equations of motion describe the orbital motion of the binary consisting of spherically symmetric nonrotating stars. The resulting equations of motion fully agree with the 3.5 PN equations of motion derived in the previous works. We also show that the locally defined energy of the star has a simple relation with its mass up to the 3.5 PN order.

We consider the electrostatic field of a point charge coupled to Hořava-Lifshitz gravity and find an exact solution describing the space with a surplus (or deficit) solid angle. Although, theoretically in general relativity, a surplus angle is hardly to be obtained in the presence of ordinary matter with positive energy distribution, it seems natural in Hořava-Lifshitz gravity. We present the sudden disappearance and reappearance of a star image as an astrophysical effect of a surplus angle. We also consider matter configurations of all possible power law behaviors coupled to Hořava-Lifshitz gravity and obtain a series of exact solutions.

We present a novel derivation of the Teukolsky-Starobinsky identities, based on properties of the confluent Heun functions. These functions define analytically all exact solutions to the Teukolsky master equation, as well as to the Regge-Wheeler and Zerilli ones. The class of solutions, subject to Teukolsky-Starobinsky type of identities is studied. Our generalization of the Teukolsky-Starobinsky identities is valid for the already studied linear perturbations to the Kerr and Schwarzschild metrics, as well as for large new classes of such perturbations which are explicitly described in the present article. Symmetry of parameters of confluent Heun’s functions is shown to stay behind the behavior of the known solutions under the change of the sign of their spin weights. A new efficient recurrent method for calculation of Starobinsky’s constant is described.

We study the nonlinear evolution of baryon acoustic oscillations in the matter power spectrum and correlation function from the improved perturbation theory (PT). Based on the framework of renormalized PT, which provides a nonperturbative way to treat the gravitational clustering of large-scale structure, we apply the closure approximation that truncates the infinite series of loop contributions at one-loop order, and obtain a closed set of integral equations for power spectrum and nonlinear propagator. The resultant integral expressions are basically equivalent to those previously derived in the form of evolution equations, and they keep important nonperturbative properties which can dramatically improve the prediction of nonlinear power spectrum. Employing the Born approximation, we then derive the analytic expressions for nonlinear power spectrum and the predictions are made for nonlinear evolution of baryon acoustic oscillations in power spectrum and correlation function. We find that the improved PT possesses a better convergence property compared with standard PT calculation. A detailed comparison between improved PT results and $N$-body simulations shows that a percent-level agreement is achieved in a certain range in power spectrum and in a rather wider range in correlation function. Combining a model of nonlinear redshift-space distortion, we also evaluate the power spectrum and correlation function in redshift space. In contrast to the results in real space, the agreement between $N$-body simulations and improved PT predictions tends to be worse, and a more elaborate modeling for redshift-space distortion needs to be developed. Nevertheless, with the currently existing model, we find that the prediction of correlation function has a sufficient accuracy compared with the cosmic-variance errors for future galaxy surveys with volume of a few $h^{-3}{\mathrm{Gpc}}^3$ at $z\gtrsim 0.5$.

We derive the expressions for the one-loop corrections in cosmological, Eulerian, perturbation theory to the matter bispectrum and to the galaxy bispectrum, assuming local galaxy bias, in the presence of non-Gaussian initial conditions. We compute them explicitly for the particular case of nonvanishing initial bispectrum and trispectrum in the local model and for a nonvanishing initial bispectrum alone for the equilateral model of primordial non-Gaussianity. While the primordial contribution to the matter bispectrum for values compatible with cosmic microwave background observations is dominant over the component due to gravitational instability at large scales, one-loop perturbative corrections due to non-Gaussian initial conditions correspond to just a few percent of the gravity-induced bispectrum at mildly nonlinear scales, similar to what happens for the matter power spectrum. However, in the perturbative expansion for the galaxy bispectrum, one-loop diagrams arising from nonlinear bias are responsible for significant large-scale contributions, indeed exceeding the primordial component, both for the local and equilateral model. We study the peculiar dependence on scale and on the shape of the triangular configurations of such additional terms, similar in their origin to the large-scale corrections to the halo and galaxy power spectra that raised significant interest in the recent literature.

Gravity probes only the total energy-momentum tensor, which leads to a perfect degeneracy for generalized dark energy models. Because of this degeneracy, ${\Omega }_m$ cannot be measured. We demonstrate this explicitly by showing that the combination of cosmic microwave background and supernova data is compatible with very large and very small values of ${\Omega }_m$ for a specific family of dark energy models. We also show that for the same reason interacting dark energy is always equivalent to a family of noninteracting models. We argue that it is better to face this degeneracy and to parametrize the actual observables.

We present an effective Lagrangian for low-scale technicolor. It describes the interactions at energies $\lesssim M_{{\rho }_T}$ of the lowest-lying bound states of the lightest technifermion doublet—the spin-one ${\rho }_T$, ${\omega }_T$, $a_T$, $f_T$, and the corresponding technipions ${\pi }_T$. This Lagrangian is intended to put on firmer ground the technicolor straw man phenomenology used for collider searches of low-scale technicolor. The technivectors are described using the hidden local symmetry (HLS) formalism of Bando, et al. The Lagrangian is based on $SU(2)\otimes U(1)\otimes U(2{)}_L\otimes U(2{)}_R$, where $SU(2)\otimes U(1)$ is the electroweak gauge group and $U(2{)}_L\otimes U(2{)}_R$ is the HLS gauge group. Special attention is paid to the higher-derivative standard HLS and Wess-Zumino-Witten interactions needed to describe radiative and other decays of $a_T$ and ${\rho }_T/{\omega }_T$, respectively.

The charge pion polarizability is calculated in the Nambu-Jona-Lasinio model, where the quark loops (in the mean field approximation) and the meson loops (in the $1/N_c$ approximation) are taken into account. We show that quark loop contribution dominates because the meson loops strongly conceal each other. The sigma-pole contribution $(m_{\sigma }^2-t{)}^{-1}$ plays the main role and contains strong $t$-dependence of the effective pion polarizability at the region $|t|\ge 4M_{\pi }^2$. Possibilities of experimental test of this sigma-pole effect in the reaction of Coulomb nuclear scattering are estimated for the COMPASS experiment.

We perform a time-dependent amplitude analysis of $B^0\to K_S^0{\pi }^{+}{\pi }^{-}$ decays to extract the $CP$ violation parameters of $f_0(980)K_S^0$ and ${\rho }^0(770)K_S^0$ and the direct $CP$ asymmetry of $K^{*+}(892){\pi }^{-}$. The results are obtained from a data sample of $(383\pm 3)\times {10}^6$ $B\overline{B}$ decays, collected with the BABAR detector at the PEP-II asymmetric–energy $B$ factory at SLAC. We find two solutions, with an equivalent goodness-of-fit. Including systematic and Dalitz plot model uncertainties, the combined confidence interval for values of the $CP$ parameter ${\beta }_{\mathrm{eff}}$ in $B^0$ decays to $f_0(980)K_S^0$ is $18°<{\beta }_{\mathrm{eff}}<76°$ at 95% confidence level (C.L). $CP$ conservation in $B^0$ decays to $f_0(980)K_S^0$ is excluded at 3.5 standard deviations including systematic uncertainties. For $B^0$ decays to ${\rho }^0(770)K_S^0$, the combined confidence interval is $-9°<{\beta }_{\mathrm{eff}}<57°$ at 95% C.L. In decays to $K^{*+}(892){\pi }^{-}$ we measure the direct $CP$ asymmetry to be $A_{CP}=-0.20\pm 0.10\pm 0.01\pm 0.02$. The measured phase difference (including $B^0{\overline{B}}^0$ mixing) between decay amplitudes of $B^0\to K^{*+}(892){\pi }^{-}$ and ${\overline{B}}^0\to K^{*-}(892){\pi }^{+}$, excludes the interval $-137°<\Delta \Phi (K^{*+}(892){\pi }^{-})<-5°$ at 95% C.L.

We study 3-form auxiliary field formulation for chiral multiplets in the Wess-Zumino model. The conventional auxiliary fields $F$ and $G$ are replaced by their Hodge duals $K_{\mu \nu \rho \sigma }$ and $H_{\mu \nu \rho \sigma }$ which are the field strengths of the 3-form potential auxiliary fields $G_{\mu \nu \rho }$ and $F_{\mu \nu \rho }$. Even though duality transformations connect these two formulations, there exist certain differences from the conventional formulation. When boundary conditions are taken into account, the field equations in the 3-form formulation are equivalent to the conventional ones, while our Lagrangian is not. We also show that the new field strengths acquire generalized Chern-Simons terms. The O’Raifeartaigh mechanism works for spontaneous supersymmetry breaking also in the 3-form auxiliary field formulation via the boundary conditions on the 3-form auxiliary fields.

Within the theoretical framework of divergence-type theories (DTTs), we set up a consistent nonlinear hydrodynamical description of a conformal fluid in flat space-time. DTTs go beyond second-order (in velocity gradients) theories, and are closed in the sense that they do not rely on adiabatic expansions. We show that the stress-energy tensor constructed from second-order conformal invariants is obtained from the DTT by a consistent adiabatic expansion. The DTT satisfies the second law, and is causal in a set of fluid states near equilibrium. Finally, we compare, analytically and numerically, the equations of motion of the DTT and its truncation to second-order terms for the case of boost invariant flow. Our numerical results indicate that the relaxation towards ideal hydrodynamics is significantly faster in the DTT than in the second-order theory. Not relying on a gradient expansion, our findings may be useful in the study of early-time dynamics and in the evolution of shock waves in heavy-ion collisions.

Recently a family of solutions of Einstein equations in backgrounds with broken Lorentz invariance was found. We show that the gravitational solution recently obtained by Kachru et al. is a part of the former solution which was derived earlier in the framework of extra-dimensional theories. We show how the energy-momentum and Einstein tensors are related and establish a correspondence between parameters which govern Lorentz invariance violation. Then we demonstrate that scaling behavior of two point correlation functions of local operators in scalar field theory is reproduced correctly for two cases with critical values of scaling parameters. Therefore, we complete the dictionary of “tree-level” duality for all known solutions of the bulk theory. In the end we speculate on relations between renormalization group flow of a boundary theory and asymptotic behavior of gravitational solutions in the bulk.

We consider a supersymmetric matrix quantum mechanics. This is obtained by adding Myers and mass terms to the dimensional reduction of 4D $\mathcal{N}=1$ super Yang-Mills theory to one dimension. Using this model we construct 4D $\mathcal{N}=1$ super Yang-Mills theory in the planar limit by using the Eguchi-Kawai equivalence. This regularization turns out to be free from the sign problem at the regularized level. The same matrix quantum mechanics is also used to provide a nonperturbative formulation of 4D $\mathcal{N}=1$ super Yang-Mills theory on a noncommutative space.

Dark strings have recently been suggested to exist in new models of dark matter that explain the excessive electronic production in the Galaxy. We study the interaction of these dark strings with semilocal strings which are solutions of the bosonic sector of the standard model in the limit${sin}^2{\theta }_w=1$, where ${\theta }_w$ is the Weinberg angle. While embedded Abelian-Higgs strings exist for generic values of the coupling constants, we show that semilocal solutions with nonvanishing condensate inside the string core exist only above a critical value of the Higgs to gauge boson mass ratio when interacting with dark strings. Above this critical value, which is greater than unity, the energy per unit length of the semilocal-dark string solutions is always smaller than that of the embedded Abelian-Higgs-dark string solutions and we show that Abelian-Higgs-dark strings become unstable above this critical value. Different from the noninteracting case, we would thus expect semilocal strings to be stable for values of the Higgs to gauge boson mass ratio larger than unity. Moreover, the one-parameter family of solutions present in the noninteracting case ceases to exist when semilocal strings interact with dark strings.

The baryon acoustic oscillation (BAO) method for constraining the expansion history is adversely affected by nonlinear structure formation, which washes out the correlation function peak created at decoupling. To increase the constraining power of low $z$ baryon acoustic oscillation experiments, it has been proposed that one use the observed distribution of galaxies to “reconstruct” the acoustic peak. Recently Padmanabhan, White, and Cohn provided an analytic formalism for understanding how reconstruction works within the context of Lagrangian perturbation theory (LPT). We extend that formalism to include the case of biased tracers of the mass in real space and, because the quantitative validity of LPT is questionable, we investigate reconstruction in $N$-body simulations. We find that LPT does a good job of explaining the trends seen in simulations for both the mass and for biased tracers in real space and comment upon the implications this has for reconstruction.

We present results obtained from a finite-element simulation of seismic displacement fields and of gravity gradients generated by those fields. The displacement field is constructed by a plane-wave model with a 3D isotropic stochastic field and a 2D fundamental Rayleigh field. The plane-wave model provides an accurate representation of stationary fields from distant sources. Underground gravity gradients are calculated as the acceleration of a free test mass inside a cavity. The results are discussed in the context of gravity-gradient noise subtraction in third generation gravitational-wave detectors. Error analysis with respect to the density of the simulated grid leads to a derivation of an improved seismometer placement inside a 3D array which would be used in practice to monitor the seismic field.

The extraction of meson-baryon scattering parameters from lattice QCD is complicated by the necessity, in some channels, of including annihilation diagrams. We consider a strategy to avoid the need for these extremely costly and noisy contributions. The strategy is based on simulations with an isospin chemical potential which, contrary to a baryon chemical potential, has no sign problem. When the isospin chemical potential is larger than a critical value, a charged pion condensate forms. Baryons propagating in the pion condensate will have their masses modified by pion-baryon scattering parameters. Consequently these parameters can be extracted from lattice QCD simulations in an isospin chemical potential, and we detail precisely which low-energy constants contribute using baryon chiral perturbation theory.