Similar to the magnification of the galaxies’ fluxes by gravitational lensing, the extinction of the fluxes by comic dust, whose existence is recently detected by [B. Ménard, R. Scranton, M. Fukugita, and G. Richards, Mon. Not. R. Astron. Soc. 405, 1025 (2010).], also modifies the distribution of a flux-selected galaxy sample. We study the anisotropic distortion by dust extinction to the 3D galaxy correlation function, including magnification bias and redshift distortion at the same time. We find the extinction distortion is most significant along the line of sight and at large separations, similar to that by magnification bias. The correction from dust extinction is negative except at sufficiently large transverse separations, which is almost always opposite to that from magnification bias (we consider a number count slope $s>0.4$). Hence, the distortions from these two effects tend to reduce each other. At low $z$ ($\lesssim 1$), the distortion by extinction is stronger than that by magnification bias, but at high $z$, the reverse holds. We also study how dust extinction affects probes in real space of the baryon acoustic oscillations (BAO) and the linear redshift distortion parameter $\beta$. We find its effect on BAO is negligible. However, it introduces a positive scale-dependent correction to $\beta$ that can be as large as a few percent. At the same time, we also find a negative scale-dependent correction from magnification bias, which is up to percent level at low $z$, but to $\sim 40\%$ at high $z$. These corrections are non-negligible for precision cosmology, and should be considered when testing General Relativity through the scale-dependence of $\beta$.

In the article Yu. N. Pokotilovski, Phys. Lett. B 686, 114 (2010), new limits on short-range, axionlike interactions are presented. In this comment, we show that the theoretical treatment of the data overestimates the sensitivity of the proposed method. We provide the corrected limits.

The bicycle model of Lorentz noninvariant neutrino oscillations without neutrino masses naturally predicts maximal mixing and a $1/E$ dependence of the oscillation argument for ${\nu }_{\mu }\to {\nu }_{\tau }$ oscillations of atmospheric and long-baseline neutrinos, but cannot also simultaneously fit the data for solar neutrinos and KamLAND. Within the standard model extension, we examine all 19 possible structures of the effective Hamiltonian for Lorentz noninvariant oscillations of massless neutrinos that naturally have a $1/E$ dependence at high neutrino energy. Because of the lack of any evidence for direction dependence, we consider only direction-independent oscillations. Although we find a number of models with a $1/E$ dependence for atmospheric and long-baseline neutrinos, none can also simultaneously fit solar and KamLAND data.

With the aim of setting constraints for the modeling of the QCD phase diagram, the phase structure of the two-flavor Polyakov-loop-extended Nambu and Jona-Lasinio (PNJL) model is investigated in the range of imaginary chemical potentials (${\mu }_{\mathrm{I}}$) and compared with available $N_f=2$ lattice QCD results. The calculations are performed using the advanced nonlocal version of the PNJL model with the inclusion of vector-type quasiparticle interactions between quarks, and with wave-function-renormalization corrections. It is demonstrated that the nonlocal PNJL model reproduces important features of QCD at finite ${\mu }_{\mathrm{I}}$, such as the Roberge-Weiss (RW) periodicity and the RW transition. Chiral and deconfinement transition temperatures for $N_f=2$ turn out to coincide both at zero chemical potential and at finite ${\mu }_{\mathrm{I}}$. Detailed studies are performed concerning the RW endpoint and its neighborhood where a first-order transition occurs.

CDF recently reported an anomaly in the $m_{jj}$ distribution of dijet events produced in association with a $W$ boson. A single $u-t-V$ flavor-changing coupling can contribute to the $m_{jj}$ anomaly while being consistent with other resonance searches. Furthermore, it gives a potential explanation of the observed forward-backward asymmetry in top quark production.

We address the issue of bound state in the two-nucleon system in lattice QCD. Our study is made in the quenched approximation at the lattice spacing of $a=0.128\mathrm{fm}$ with a heavy quark mass corresponding to $m_{\pi }=0.8\mathrm{GeV}$. To distinguish a bound state from an attractive scattering state, we investigate the volume dependence of the energy difference between the ground state and the free two-nucleon state by changing the spatial extent of the lattice from 3.1 fm to 12.3 fm. A finite energy difference left in the infinite spatial volume limit leads us to the conclusion that the measured ground states for not only spin triplet but also singlet channels are bounded. Furthermore the existence of the bound state is confirmed by investigating the properties of the energy for the first excited state obtained by a $2\times 2$ diagonalization method. The scattering lengths for both channels are evaluated by applying the finite volume formula derived by Lüscher to the energy of the first excited states.

We explore the possibility that the large $t\overline{t}$ forward-backward asymmetry measured by the CDF detector at Tevatron could be due to a universal effective axial-vector coupling of gluon. Using an effective field theory approach we show model independently how such a log-enhanced coupling occurs at 1-loop level. The interference with QCD gluon vector coupling naturally induces the observed positive forward-backward $t\overline{t}$ asymmetry that grows with $t\overline{t}$ invariant mass and is consistent with the cross section measurements. This scenario does not involve new flavor changing couplings nor operators that interfere with QCD, and, therefore, is not constrained by the LHC searches for 4-quark contact interactions. We predict top quark polarization effects that grow with energy and allow to test this scenario at the LHC. Our proposal offers a viable alternative to new physics scenarios that explain the $t\overline{t}$ forward-backward asymmetry anomaly with the interference between QCD and tree level new physics amplitudes.

We present the complete calculations of the forward-backward asymmetry ($A_{\mathrm{FB}}$) and the total cross section of top quark pair production induced by dimension-six four quark operators at the Tevatron up to $\mathcal{O}({\alpha }_s^2/{\Lambda }^2)$. Our results show that next-to-leading order QCD corrections can change $A_{\mathrm{FB}}$ and the total cross section by about 10%. Moreover, next-to-leading order QCD corrections reduce the dependence of $A_{\mathrm{FB}}$ and total cross section on the renormalization and factorization scales significantly. We also evaluate the total cross section and the charge asymmetry ($A_{\mathrm{C}}$) induced by these operators at the Large Hadron Collider (LHC) up to $\mathcal{O}({\alpha }_s^2/{\Lambda }^2)$, for the parameter space allowed by the Tevatron data. We find that the value of $A_{\mathrm{C}}$ induced by these operators is much larger than standard model prediction, and LHC has potential to discover these new physics effects when the measurement precision increases.

We study the consequences on the neutrino oscillation parameter space, mixing angle (${tan}^2\theta$), and vacuum mass difference ($\Delta m_0^2$) when mass varying neutrino (MaVaN) models are assumed in a supernova environment. We consider electronic to sterile channels ${\nu }_e\to {\nu }_s$ and ${\overline{\nu }}_e\to {\overline{\nu }}_s$ in two-flavor scenario. In a given model of MaVaN mechanism, we induce a position-dependent effective mass difference, $\Delta {\tilde{m}}^2(r)$, where $r$ is the distance from the supernova core, that changes the neutrino and antineutrino flavor conversion probabilities. We study the constraints on the mixing angle and vacuum mass difference coming from r-process and the SN1987A data. Our result is the appearance of a new exclusion region for very small mixing angles, ${tan}^2\theta ={10}^{-6}–{10}^{-2}$, and small vacuum mass difference, $\Delta m_0^2=1–20{\mathrm{eV}}^2$, due the MaVaN mechanism.

We construct a class of two Higgs doublets models with a 4th sequential generation of fermions that may effectively accommodate the low-energy characteristics and phenomenology of a dynamical electroweak symmetry breaking scenario which is triggered by the condensates of the 4th family fermions. In particular, we single out the heavy quarks by coupling the heavier Higgs doublet (${\Phi }_h$) which possesses a much larger VEV only to them while the lighter doublet (${\Phi }_{\ell }$) couples only to the light fermions. We study the constraints on these models from precision electroweak data as well as from flavor data. We also discuss some distinct new features that have direct consequences on the production and decays of the 4th family quarks and leptons in high-energy colliders;, in particular, the conventional search strategies for $t^{\prime }$ and $b^{\prime }$ may need to be significantly revised.

The rare decay $K_L^0\to {\pi }^0{\pi }^0\nu \overline{\nu }$ was studied with the E391a detector at the KEK 12-GeV proton synchrotron. Based on $9.4\times {10}^9$ $K_L^0$ decays, an upper limit of $8.1\times {10}^{-7}$ was obtained for the branching fraction at 90% confidence level. We also set a limit on the $K_L^0\to {\pi }^0{\pi }^{0}X$ ($X\to \mathrm{\text{invisible particles}}$) process; the limit on the branching fraction varied from $7.0\times {10}^{-7}$ to $4.0\times {10}^{-5}$ for the mass of $X$ ranging from $50\mathrm{MeV}/c^2$ to $200\mathrm{MeV}/c^2$.

We study the structure of $SU(5)$ $F$-theory grand unified theory (GUT) models that engineer additional $U(1)$ symmetries. These are highly constrained by a set of relations observed by Dudas and Palti (DP) that originate from the physics of four-dimensional anomaly cancellation. Using the DP relations, we describe a general tension between unification and the suppression of dimension 5 proton decay when one or more $U(1)$’s are Peccei-Quinn (PQ) symmetries and hypercharge flux is used to break the $SU(5)$ GUT group. We then specialize to spectral cover models, whose global completions in $F$ theory we know how to construct. In that setting, we provide a technical derivation of the DP relations, construct spectral covers that yield all possible solutions to them, and provide a complete survey of spectral cover models for $SU(5)$ GUTs that exhibit two $U(1)$ symmetries.

We consider the small separation asymptotic expansions of the Casimir interaction energy and the Casimir interaction force between two parallel cylinders. The leading order terms and the next-to-leading order terms are computed analytically. Four combinations of boundary conditions are considered, which are Dirichlet-Dirichlet, Neumann-Neumann, Dirichlet-Neumann, and Neumann-Dirichlet. For the case where one cylinder is inside another cylinder, the computations are shown in detail. In this case, we restrict our attention to the situation where the cylinders are strictly eccentric and the distance between the cylinders $d$ is much smaller than the distance between the centers of the cylinders. The computations for the case where the two cylinders are exterior to each other can be done in the same way and we only present the results, which turn up to be similar to the results for the case where one cylinder is inside another except for some changes of signs. In all the scenarios we consider, the leading order terms are of order $d^{-7/2}$ and they agree completely with the proximity force approximations. The results for the next-to-leading order terms are new. In the limiting case where the radius of the larger cylinder approaches infinity, the well-known results for the cylinder-plate configuration with Dirichlet-Dirichlet or Neumann-Neumann boundary conditions are recovered.

Because of its versatility, the 2-form field has been employed to describe a multitude of scenarios that range from high energy to condensed matter physics. Pushing forward in this endeavor we study the interaction energy, intermediated by this kind of field, between branes in a variety of configurations. Also, the so-called Cremmer-Scherk-Kalb-Ramond model, which consists of the electromagnetic field coupled to the Kalb-Ramond gauge potential, is considered. It turns out that these models exhibit a much richer class of sources than usually thought, able to intermediate novel forms of interactions in different scenarios.

In this work, we apply the Matsubara-Fradkin formalism and the Nakanishi’s auxiliary field method to the quantization of the Podolsky electrodynamics in thermodynamic equilibrium. This approach allows us to write consistently the path integral representation for the partition function of gauge theories in a simple manner. Furthermore, we find the Dyson-Schwinger-Fradkin equations and the Ward-Fradkin-Takahashi identities for the Podolsky theory. We also write the most general form for the polarization tensor in thermodynamic equilibrium.

Very recently Ali et al. (2009) proposed a new generalized uncertainty principle (with a linear term in Plank length which is consistent with doubly special relativity and string theory. The classical and quantum effects of this generalized uncertainty principle (termed as modified uncertainty principle or MUP) are investigated on the phase space of a dilatonic cosmological model with an exponential dilaton potential in a flat Friedmann-Robertson-Walker background. Interestingly, as a consequence of MUP, we found that it is possible to get a late time acceleration for this model. For the quantum mechanical description in both commutative and MUP framework, we found the analytical solutions of the Wheeler-DeWitt equation for the early universe and compare our results. We have used an approximation method in the case of MUP.

We study a vacuum Bianchi IX universe in the context of Hořava-Lifshitz gravity. In particular, we focus on the classical dynamics of the universe and analyze how anisotropy changes the history of the universe. For small anisotropy, we find an oscillating universe as well as a bounce universe just as the case of the Friedmann-Lemaitre-Robertson-Walker spacetime. However, if the initial anisotropy is large, we find the universe which ends up with a big crunch after oscillations if a cosmological constant $\Lambda$ is zero or negative. For $\Lambda >0$, we find a variety of histories of the universe, that is a de Sitter expanding universe after oscillations in addition to the oscillating solution and the previous big crunch solution. This fate of the universe shows sensitive dependence of initial conditions, which is one of the typical properties of a chaotic system. If the initial anisotropy is near the upper bound, we find the universe starting from a big bang and ending up with a big crunch for $\Lambda \le 0$, and a de Sitter expanding universe starting from a big bang for $\Lambda >0$.

Accurate knowledge of the gravitational-wave (GW) signal from inspiraling compact binaries is essential to detect these signatures in the data from GW interferometers. With recent advances in post-Newtonian (PN) theory and numerical relativity (NR) it has become possible to construct inspiral-merger-ringdown waveforms by combining both descriptions into one complete hybrid signal. While addressing the reliability of such waveforms in different points of the physical parameter space, previous studies have identified the PN contribution as the dominant source of error, which can be reduced by incorporating longer NR simulations. In this paper we overcome the two outstanding issues that make it difficult to determine the minimum simulation length necessary to produce suitably accurate hybrids for GW astronomy applications: (1) the relevant criteria for a GW search is the mismatch between the true waveform and a set of model waveforms, optimized over all waveforms in the model, but for discrete hybrids this optimization was not yet possible. (2) these calculations typically require that numerical waveforms already exist, while we develop an algorithm to estimate hybrid mismatch errors without numerical data, which enables us to estimate the necessary NR waveform length before performing the simulation. Our procedure relies on combining supposedly equivalent PN models at highest available order with common data in the NR regime, and their difference serves as a measure of the uncertainty assumed in each waveform. Contrary to some earlier studies, we estimate that $\sim 10$ NR orbits before merger should allow for the construction of waveform families that are accurate enough for detection in a broad range of parameters, only excluding highly spinning, unequal-mass systems. Nonspinning systems, even with high mass-ratio ($q\gtrsim 20$) are well modeled for astrophysically reasonable component masses. In addition, the parameter bias is only of the order of 1% for total mass and symmetric mass-ratio and less than 0.1 for the dimensionless spin magnitude. We take the view that similar NR waveform lengths will remain the state of the art in the advanced detector era, and begin to assess the limits of the science that can be done with them.

We show that the nonlinear massive gravity model of de Rham, Gabadadze, and Tolley admits exact plane gravitational wave solution whose waveform obeys the two-dimensional Helmholtz equation. The solution is valid for arbitrary values of the coefficients of the cubic and quartic terms. In the massless limit the solution reduces to the Aichelburg-Sexl metric in general relativity.

We perform a fully nonlinear analysis of superhorizon perturbation in Hořava-Lifshitz gravity, based on the gradient expansion method. We present a concrete expression for the solution of gravity equations up to the second order in the gradient expansion, and prove that the solution can be extended to any order. The result provides yet another example for analogue of the Vainshtein effect: the nonlinear solution is regular in the limit $\lambda \to 1$ and recovers general relativity coupled to dark matter at low energy. Finally, we propose a definition of nonlinear curvature perturbation $\mathcal{R}$ in Hořava-Lifshitz gravity and show that it is conserved up to the first order in the gradient expansion.