With the availability of thousands of type Ia supernovae in the near future the magnitude scatter induced by lensing will become a major issue as it affects parameter estimation. Current $N$-body simulations are too time consuming to be integrated in the likelihood analyses used for estimating the cosmological parameters. In this paper we show that in the weak-lensing regime a statistical numerical approximation produces accurate results orders of magnitude faster. We write down simple fits to the second, third and fourth central moments of the lensing magnification probability distribution as a function of redshift, of the power spectrum normalization and of the present-day matter density. We also improve upon existing models of lensing variance and show that a shifted log-normal distribution fits well the numerical one. These fits can be easily employed in cosmological likelihood analyses. Moreover, our theoretical predictions make it possible to invert the problem and begin using supernovae lensing to constrain the cosmological parameters.

We attempt to make a direct measurement of the weak lensing signal from the WMAP 7-year data. We apply the real-space implementation of the optimal quadratic estimator on the maps produced by the W-band differencing assemblies. We obtain a weak lensing amplitude parameter of $A_L=0.99\pm 1.67$ after correcting for several sources of bias. The error budget includes a contribution from the bias removal procedure. Despite the demonstrated insensitivity of the real-space estimator to uncorrelated noise, we conclude that this detection is not statistically significant. We expect that a full-sky, higher-sensitivity experiment such as Planck will allow us to make a more significant measurement.

The maximum entropy method is used to compute the quark spectral function at nonzero temperature. We solve the gap equation of quantum chromodynamics (QCD) self-consistently, employing a rainbow kernel which phenomenologically models results from Dyson-Schwinger equations and lattice QCD. We use the criterion of positivity restoration of the spectral function as a signal for deconfinement. Our calculation indicates that the critical temperature of deconfinement $T_d$ is slightly smaller than the one of chiral symmetry restoration $T_c$: $T_d\sim 94\%T_c$ in the chiral limit and $T_d\sim 96\%T_c$ with physical light quark masses. Since these deviations are within the systematic error of our approach, it is reasonable to conclude that chiral symmetry restoration and deconfinement coincide at zero chemical potential.

We investigate the effects of messenger–matter mixing on the lightest $CP$–even Higgs boson mass $m_h$ in gauge–mediated supersymmetry breaking models. It is shown that with such mixings $m_h$ can be raised to about 125 GeV, even when the superparticles have sub–TeV masses, and when the gravitino has a cosmologically preferred sub-keV mass. In minimal gauge mediation without messenger-matter mixing, realizing $m_h\sim 125\mathrm{GeV}$ would require multi-TeV supersymmetry spectrum. The increase in $m_h$ due to messenger–matter mixing is maximal in the case of messengers belonging to $10+\overline{10}$ of $SU(5)$ unification, while it is still significant when they belong to $5+\overline{5}$ of $SU(5)$. Our results are compatible with gauge coupling unification, perturbativity, and the unification of messenger Yukawa couplings. We embed these models into a grand unification framework with a $U(1)$ flavor symmetry that addresses the fermion mass hierarchy and generates naturally large neutrino mixing angles. While supersymmetry mediated flavor changing processes are sufficiently suppressed in such an embedding, small new contributions to $K^0-\overline{K^0}$ mixing can resolve the apparent discrepancy in the $CP$ asymmetry parameters $\sin 2\beta$ and ${ϵ}_K$.

Several extensions of the standard model have light doubly charged Higgs bosons in their particle spectrum. The supersymmetric versions of these models introduce fermionic superpartners of these doubly charged Higgs bosons, the Higgsinos, which also remain light. In this work we analyze a new collider signal resulting from the pair production and decay of a light doubly charged Higgsino to an even lighter doubly charged Higgs boson. We focus on the minimal left-right supersymmetric model with automatic $R$-parity conservation, which predicts such a light doubly charged Higgs boson and its Higgsino partner at the TeV scale, which are singlets of $SU(2{)}_L$. We investigate the distinctive signatures of these particles with four leptons and missing transverse energy in the final state at the Large Hadron Collider and show that the discovery reach for both particles can be increased in this channel.

We extend the nonrelativistic QCD (NRQCD) prediction for the production of heavy quarkonium with low transverse momentum in hadronic collisions by taking into account effects from all-order soft gluon resummation. Following the Collins-Soper-Sterman formalism, we resum the most singular terms in the partonic subprocesses. The theoretical predictions of $J/\psi$ and ${\rm Y}$ productions are compared to the experimental data from the fixed target experiments (E866) and the collider experiments (RHIC, Tevatron, LHC). The associated nonperturbative Sudakov form factor for the gluon distributions is found to be different from the previous assumption of rescaling the quark form factor by the ratio of color factors. This conclusion should be further checked by future experiments on Higgs boson and/or diphoton production in $pp$ collisions. We also comment on the implication of our results on determining the color-octet matrix elements associated with the $J/\psi$ and ${\rm Y}$ productions in the NRQCD factorization formalism.

Among the newly observed structures in the heavy-quarkonium mass region, some have been proposed to be hadronic molecules. We investigate the consequences of heavy-quark flavor symmetry on these heavy meson hadronic molecules. The symmetry allows us to predict new hadronic molecules on one hand, and test the hadronic molecular assumption of the observed structures on the other hand. We explore the consequences of the flavor symmetry assuming the $X(3872)$ and $Z_b(10610)$ as an isoscalar $D{\overline{D}}^{*}$ and isovector $B{\overline{B}}^{*}$ hadronic molecule, respectively. A series of hadronic molecules composed of heavy mesons are predicted. In particular, there is an isoscalar $1^{++}$ $B{\overline{B}}^{*}$ bound state with a mass about 10 580 MeV which may be searched for in the ${\rm Y}(1S,2S){\pi }^{+}{\pi }^{-}{\pi }^0$ mass distribution; the isovector charmonium partners of the $Z_b(10610)$ and the $Z_b(10650)$ are also predicted, which probably corresponds to the very recently observed $Z_c(3900)$ and $Z_c(4025)$ resonances by the BESIII Collaboration.

We derive an expression for the heavy quark damping rate in hot quark gluon plasma in the presence of flow. Here all the bath particles are out of equilibrium due to the existence of nonzero velocity gradient. The magnetic sector shows similar infrared divergences even after hard thermal loop corrections as one encounters in the case of nonviscous plasma. We estimate the first order correction in ($\eta /s$) for heavy quark damping rate due to the nonzero viscosity of the QCD plasma.

We study the effect of the meson cloud dressing in the octet baryon to decuplet baryon electromagnetic transitions. Combining the valence-quark contributions from the covariant spectator quark model with those of the meson cloud estimated based on the flavor SU(3) cloudy bag model, we calculate the transition magnetic form factors at $Q^2=0$ ($Q^2=-q^2$ and $q$ the four-momentum transfer), and also the decuplet baryon electromagnetic decay widths. The result for the ${\gamma }^{*}\Lambda \to {\Sigma }^{*0}$ decay width is in complete agreement with the data, while that for the ${\gamma }^{*}{\Sigma }^{+}\to {\Sigma }^{*+}$ is underestimated by 1.4 standard deviations. This achievement may be regarded as a significant advance in the present theoretical situation.

We obtain a Schwarzschild and Reissner-Nordstrom emergent black holes by exploring the torsion dynamics in a generalized curvature formulation, underlying an effective $D_4$-brane on $S^1$. It is shown that a constant effective metric, sourced by a background fluctuation in $B_2$ potential, on a $D_3$-brane receives a dynamical quantum correction in the presence of an electric charge.

We show that the asymptotically flat hairy black holes, solutions of the Einstein field equations minimally coupled to a scalar field, previously discovered by one of us, present mode instability against linear radial perturbations. It is also shown that the number of unstable modes is finite and their frequencies can be made arbitrarily small.

Lovelock gravity is a class of higher-derivative gravitational theories for which the linearized equations of motion have no more than two time derivatives. Here, it is shown that any Lovelock theory can be effectively described as Einstein gravity coupled to a p-form gauge field. This extends the known example of an $f(R)$ theory of gravity, which can be described as Einstein gravity coupled to a scalar field.

We describe in detail the implementation of a simplified approach to radiative transfer in general relativity by means of the well-known neutrino leakage scheme (NLS). In particular, we carry out an extensive investigation of the properties and limitations of the NLS for isolated relativistic stars to a level of detail that has not been discussed before in a general-relativistic context. Although the numerous tests considered here are rather idealized, they provide a well-controlled environment in which to understand the relationship between the matter dynamics and the neutrino emission, which is important in order to model the neutrino signals from more complicated scenarios, such as binary neutron-star mergers. When considering nonrotating hot neutron stars we confirm earlier results of one-dimensional simulations, but also present novel results about the equilibrium properties and on how the cooling affects the stability of these configurations. In our idealized but controlled setup, we can then show that deviations from the thermal and weak-interaction equilibrium affect the stability of these models to radial perturbations, leading models that are stable in the absence of radiative losses, to a gravitational collapse to a black hole when neutrinos are instead radiated.

We show that the geodesic motion in the Zipoy-Voorhees space-time is not Liouville integrable, in that there does not exist an additional first integral meromorphic in the phase-space variables.

In this paper, we study the effects of parity violation on non-Gaussianities of primordial gravitational waves in the framework of the Hořava-Lifshitz theory of gravity, in which high-order spatial derivative operators, including the ones violating parity, generically appear. By calculating the three-point function, we find that the leading-order contributions to the non-Gaussianities come from the usual second-order derivative terms, which produce the same bispectrum as that found in general relativity. The contributions from high-order spatial $n$th derivative terms are always suppressed by a factor $(H/M_{*}{)}^{n-2}(n\ge 3)$, where $H$ denotes the inflationary energy and $M_{*}$ the suppression mass scale of the high-order spatial derivative operators of the theory. Therefore, the next leading-order contributions come from the three-dimensional gravitational Chern-Simons term. With some reasonable arguments, it is shown that this three-dimensional operator is the only one that violates the parity and in the meantime has nonvanishing contributions to non-Gaussianities.

We provide a detailed treatment and comparison of the weak lensing effects due to large scale structure (LSS), or scalar density perturbations and those due to gravitational waves (GWs) or tensor perturbations, on the temperature and polarization power spectra of the cosmic microwave background (CMB). We carry out the analysis both in real space by using the correlation function method, as well as in the spherical harmonic space. We find an intriguing similarity between the lensing kernels associated with LSS lensing and GW lensing. It is found that the lensing kernels only differ in relative negative signs and their form is very reminiscent of even and odd parity bipolar spherical harmonic coefficients. Through a numerical study of these lensing kernels, we establish that lensing due to GW is more efficient at distorting the CMB spectra as compared to LSS lensing, particularly for the polarization power spectra. Finally we argue that the CMB $B$-mode power spectra measurements can be used to place interesting constraints on GW energy densities.

The isospin violating dark matter (IVDM) scenario offers an interesting possibility to reconcile conflicting results among direct dark matter search experiments for a mass range around 10 GeV. We consider two simple renormalizable IVDM models with a complex scalar dark matter and a Dirac fermion dark matter, respectively, whose stability is ensured by the conservation of “dark matter number.” Although both models successfully work as the IVDM scenario with destructive interference between effective couplings to proton and neutron, the dark matter annihilation cross section is found to exceed the cosmological/astrophysical upper bounds. Then, we propose a simple scenario to reconcile the IVDM scenario with the cosmological/astrophysical bounds, namely, the IVDM being asymmetric. Assuming a suitable amount of dark matter asymmetry has been generated in the early Universe, the annihilation cross section beyond the cosmological/astrophysical upper bound nicely works to dramatically reduce the antidark matter relic density and as a result, the constraints from dark matter indirect searches are avoided. We also discuss collider experimental constraints on the models and an implication to Higgs boson physics.

Compact binary systems with neutron stars or black holes are one of the most promising sources for ground-based gravitational-wave detectors. Gravitational radiation encodes rich information about source physics; thus parameter estimation and model selection are crucial analysis steps for any detection candidate events. Detailed models of the anticipated waveforms enable inference on several parameters, such as component masses, spins, sky location and distance, that are essential for new astrophysical studies of these sources. However, accurate measurements of these parameters and discrimination of models describing the underlying physics are complicated by artifacts in the data, uncertainties in the waveform models and in the calibration of the detectors. Here we report such measurements on a selection of simulated signals added either in hardware or software to the data collected by the two LIGO instruments and the Virgo detector during their most recent joint science run, including a “blind injection” where the signal was not initially revealed to the collaboration. We exemplify the ability to extract information about the source physics on signals that cover the neutron-star and black-hole binary parameter space over the component mass range $1{\mathrm{M}}_{\odot }–25{\mathrm{M}}_{\odot }$ and the full range of spin parameters. The cases reported in this study provide a snapshot of the status of parameter estimation in preparation for the operation of advanced detectors.

We address several aspects of lattice QCD calculations of the hadronic vacuum polarization and the associated Adler function. We implement a representation derived previously which allows one to access these phenomenologically important functions for a continuous set of virtualities, irrespective of the flavor structure of the current. Secondly, we present a theoretical analysis of the finite-size effects on our particular representation of the Adler function, based on the operator product expansion at large momenta and on the spectral representation of the Euclidean correlator at small momenta. Finally, an analysis of the flavor structure of the electromagnetic current correlator is performed, where a recent theoretical estimate of the Wick-disconnected diagram contributions is rederived independently and confirmed.

Neutral flavor-changing transitions are hugely suppressed in the Standard Model and therefore they are very sensitive to new physics. We consider the decay rate of $t\to u_{i}h$ where $u_i=u$, $c$ using an effective field theory approach. We perform the calculation at next-to-leading order (NLO) in QCD including the relevant dimension-six operators. We find that at NLO the contribution from the flavor-changing chromomagnetic operator is as important as the standard QCD correction to the flavor-changing Yukawa coupling. In addition to improving the accuracy of the theoretical predictions, the NLO calculation provides information on the operator mixing under the renormalization group.