We consider  $\mathcal{N}=(1,1)$ super Yang-Mills theory in $1+1$ dimensions with fundamentals at large $N_c$. A Chern-Simons term is included to give mass to the adjoint partons. Using the spectrum of the theory, we calculate thermodynamic properties of the system as a function of the temperature and the Yang-Mills coupling. In the large-$N_c$ limit there are two noncommunicating sectors, the glueball sector, which we presented previously, and the mesonlike sector that we present here.  We find that the mesonlike sector dominates the thermodynamics. Like the glueball sector, the meson sector has a Hagedorn temperature $T_H$, and we show that the Hagedorn temperature grows with the coupling. We calculate the temperature and coupling dependence of the free energy for temperatures below $T_H$. As expected, the free energy for weak coupling and low temperature grows quadratically with the temperature. Also the ratio of the free energies at strong coupling compared to weak coupling, $r_{s-w}$, for low temperatures grows quadratically with $T$. In addition, our data suggest that $r_{s-w}$ tends to zero in the continuum limit at low temperatures.

A version of the virial theorem, which takes into account the effects of the noncompact extra dimensions, is derived in the framework of the brane world models. In the brane world scenario, the four-dimensional effective Einstein equation has some extra terms, called dark radiation and dark pressure, respectively, which arise from the embedding of the 3-brane in the bulk. To derive the generalized virial theorem, we use a method based on the collisionless Boltzmann equation. The dark radiation term generates an equivalent mass term (the dark mass), which gives an effective contribution to the gravitational energy. This term may account for the well-known virial theorem mass discrepancy in actual clusters of galaxies. An approximate solution of the vacuum field equations on the brane, corresponding to weak gravitational fields, is also obtained, and the expressions for the dark radiation and dark mass are derived. The qualitative behavior of the dark mass is similar to that of the observed virial mass in clusters of galaxies. We compare our model with the observational data for galaxy clusters, and we express all the physical parameters of the model in terms of observable quantities. In particular, we predict that the dark mass must extend far beyond the presently considered virial radius. The behavior of the galaxy cluster velocity dispersion in brane world models is also considered. Therefore the study of the matter distribution and velocity dispersion at the extragalactic scales could provide an efficient method for testing the multidimensional physical models.

We show that the vorticity appearing in stationary vacuum spacetimes is always related to the existence of a flow of superenergy on the plane orthogonal to the vorticity vector. This result, together with the previously established link between vorticity and superenergy in radiative (Bondi-Sachs) spacetimes, strengthens further the case for this latter quantity as the cause of frame dragging.

We construct a conserved, symmetric energy-momentum (pseudo-)tensor for Chern-Simons modified gravity, thus demonstrating that the theory is Lorentz invariant. The tensor is discussed in relation to other gravitational energy-momentum tensors and analyzed for the Schwarzschild, Reissner-Nordstrom, and Friedmann-Robertson-Walker solutions. To our knowledge this is the first confirmation that the Reissner-Nordstrom and Friedmann-Robertson-Walker metrics are solutions of the modified theory.

Warm inflation scenarios are studied with the dissipative coefficient computed in the equilibrium approximation. Use is made of the analytical expressions available in the low temperature regime with focus on the possibility of achieving strong dissipation within this approximation. Two different types of models are examined: monomial or equivalently chaotic type potentials, and hybrid like models where the energy density during inflation is dominated by the false vacuum. In both cases dissipation is shown to typically increase during inflation and bring the system into the strong dissipative regime. Observational consequences are explored for the amplitude of the primordial spectrum and the spectral index, which translate into constraints on the number of fields mediating the dissipative mechanism, and the number of light degrees of freedom produced during inflation. This paper furthers the foundational development of warm inflation dynamics from first principles quantum field theory by calculating conservative lower bound estimates on dissipative effects during inflation using the well established thermal equilibrium approximation. This approximation does not completely represent the actual physical system and earlier work has shown relaxing both the equilibrium and low temperature constraints can substantially enlarge the warm inflation regime, but these improvements still need further theoretical development.

The most common way to simplify extensive Monte Carlo simulations of air showers is to use the thinning approximation. We study its effect on the physical parameters reconstructed from simulated showers. To this end, we have created a library of showers simulated without thinning with energies from ${10}^{17}\mathrm{eV}$ to ${10}^{18}\mathrm{eV}$, various zenith angles, and primaries. This library is publicly available. Physically interesting applications of the showers simulated without thinning are discussed. Observables reconstructed from these showers are compared to those obtained with the thinning approximation. The amount of artificial fluctuations introduced by thinning is estimated. A simple method, multisampling, is suggested which results in a controllable suppression of artificial fluctuations and at the same time requires less demanding computational resources as compared to the usual thinning.

Following recent predictions that the geometric scaling properties of deep inelastic scattering data in inclusive ${\gamma }^{*}p$ collisions are expected also in exclusive diffractive processes, we investigate the diffractive production of vector mesons. Using analytic results in the framework of the Balitsky-Kovchegov (BK) equation at nonzero momentum transfer, we extend to the nonforward amplitude a QCD-inspired forward saturation model including charm, following the theoretical predictions for the momentum transfer dependence of the saturation scale. We obtain a good fit to the available HERA data and make predictions for deeply virtual Compton scattering measurements.

We have studied a leptogenesis scenario in the framework of the minimal seesaw model with tribimaximal mixing. Usually, at least one of the elements in the Dirac mass matrix is fixed to be zero, for example, we denote it by $b_2=0$. We have pointed out that the absolute value of the $CP$ asymmetry has several minimums and maximums with nonzero $b_2$. Thus one can expect that more rich phenomena, such as an enhanced leptogenesis, are hidden in the $b_2\ne 0$ space.

The aim of this Comment is to call to the attention of double special relativity (DSR) readers a basic fact. The introduction of noncommutative structures in problems like the one addressed by Ghosh [ Phys. Rev. D 74, 084019 (2006)] is not necessary for the understanding of DSR physics. It can be described just as the relativistic free particle problem in a different parametrization.

A new kind of delta expansion is applied on the lattice to the $d=2$ nonlinear $\sigma$ model at $N=\infty$ and $N=1$ which corresponds to the Ising model. We introduce the parameter $\delta$ for the dilation of the scaling region of the model with the replacement of the lattice spacing $a$ to $(1-\delta {)}^{1/2}a$. Then, we demonstrate that the expansion in $\delta$ admits an approximation of the scaling behavior of the model at both limits of $N$ from the information at a large lattice spacing $a$.

There exists the standard quantum limit (SQL), derived from Heisenberg’s uncertainty relation, in the sensitivity of laser interferometer gravitational-wave (GW) detectors. However, in the context of a full quantum-mechanical approach, SQL can be overcome using the correlation of shot noise and radiation-pressure noise. So far, signal recycling, which is one of the methods to overcome SQL, is considered only in a recombined-type interferometer such as Advanced LIGO, LCGT, and GEO600. In this paper, we investigated quantum noise and the possibility of signal recycling in a differential-type interferometer. As a result, we found that signal recycling is possible and creates at most three dips in the sensitivity curve of the detector due to two coupled resonators. The additional third dip makes it possible to decrease quantum noise at low frequencies, keeping the moderate sensitivity at high frequencies. Then, taking advantage of the third dip and comparing the sensitivity of a differential-type interferometer with that of a next-generation Japanese GW interferometer, LCGT, we found that signal-to-noise ratio (SNR) of inspiral binary is improved by a factor of $\approx 1.43$ for neutron star binary, $\approx 2.28$ for $50M_{\odot }$ black hole binary, and $\approx 2.94$ for $100M_{\odot }$ black hole binary. We also found that power recycling to increase laser power is possible in our signal-recycling configuration of a detector.

We show that the annihilation of vortex-antivortex pairs can lead to very long-lived oscillon states in 2d Abelian Higgs models. The emergence of oscillons is controlled by the ratio of scalar and vector field masses, $\beta =(m_s/m_v{)}^2$ and can be described as a phase transition in field configuration space with critical value ${\beta }_c\simeq 0.13(6)\pm 2$: only models with $\beta <{\beta }_c$ lead to oscillonlike remnants. The critical behavior of the system obeys a power law $O(\beta )\sim |\beta -{\beta }_c{|}^o$, where $O$ is an order parameter indicating the presence of oscillons and $o=0.2(2)\pm 2$ is the critical exponent.

In this article we analyze the impact of B physics and Higgs physics at LEP on standard and nonstandard Higgs bosons searches at the Tevatron and the LHC, within the framework of minimal flavor violating supersymmetric models. The B-physics constraints we consider come from the experimental measurements of the rare B decays $b\to s\gamma$ and $B_u\to \tau \nu$ and the experimental limit on the $B_s\to {\mu }^{+}{\mu }^{-}$ branching ratio. We show that these constraints are severe for large values of the trilinear soft breaking parameter $A_t$, rendering the nonstandard Higgs searches at hadron colliders less promising. On the contrary these bounds are relaxed for small values of $A_t$ and large values of the Higgsino mass parameter $\mu$, enhancing the prospects for the direct detection of nonstandard Higgs bosons at both colliders. We also consider the available ATLAS and CMS projected sensitivities in the standard model Higgs search channels, and we discuss the LHC’s ability in probing the whole MSSM parameter space. In addition we also consider the expected Tevatron collider sensitivities in the standard model Higgs $h\to b\overline{b}$ channel to show that it may be able to find $3\sigma$ evidence in the B-physics allowed regions for small or moderate values of the stop mixing parameter.

We provide the first evidence of a walking dynamics for two color lattice Yang-Mills theory with two Dirac flavors in the symmetric representation of the gauge group.

The Fourier transform of the generalized parton distributions (GPDs) at zero skewness with respect to the transverse momentum transfer gives the distribution of partons in the impact parameter space. We investigate the GPDs as well as the impact parameter dependent parton distributions (ipdpdfs) by expressing them in terms of overlaps of light-front wave functions (LFWFs) and present a comparative study using three different model LFWFs.

The color antitriplet triquark $q\overline{q}\overline{q}$ is considered as a compact component in the tetraquark structure $cq\overline{q}\overline{q}$ of exotic $D_s$ mesons. We discuss the mass spectrum and the flavor mixing of the triquarks by using the instanton induced interaction and the one-gluon exchange potentials. As a characteristic property of the triquark, we investigate the isospin violation. It is shown that the flavor $\overline{\mathbf{3}}$ (isosinglet) and $\mathbf{6}$ (isotriplet) states may be strongly mixed and then are identified with $D_s(2632)$.

We use the variational method within the Hamiltonian formalism of quantum field theory to derive relativistic two-, (four)-, and (six)-body wave equations for scalar particles interacting via a massive or massless mediating scalar field (the scalar Yukawa model). Fock-space variational trial states [$2+(4)+(6)$] are used to derive the relativistic two-body system. The equations are shown to have the Schrödinger nonrelativistic limit, with Coulombic interparticle potentials in the case of a massless mediating field and Yukawa interparticle potentials in the case of a massive mediating field. The results show that the inclusion of virtual pairs has a large effect for the binding energy of the system at strong coupling. In the case of the discovery of a scalar Higgs particle in upcoming experiments, we may apply the present results to real, physical systems.

We consider a dynamical system of phantom scalar field under exponential potential in the background of loop quantum cosmology. In our analysis, there is neither stable node nor repeller unstable node but only two saddle points, hence no big rip singularity. Physical solutions always possess potential energy greater than the magnitude of the negative kinetic energy. We found that the universe bounces after accelerating even in the domination of the phantom field. After bouncing, the universe finally enters the oscillatory regime.

We compute the expected value of the cosmological constant in our universe from the causal entropic principle. Since observers must obey the laws of thermodynamics and causality, the principle asserts that physical parameters are most likely to be found in the range of values for which the total entropy production within a causally connected region is maximized. Despite the absence of more explicit anthropic criteria, the resulting probability distribution turns out to be in excellent agreement with observation. In particular, we find that dust heated by stars dominates the entropy production, demonstrating the remarkable power of this thermodynamic selection criterion. The alternative approach—weighting by the number of “observers per baryon”—is less well-defined, requires problematic assumptions about the nature of observers, and yet prefers values larger than present experimental bounds.

We present a simple formula for the radiated angular momentum based on a spin-weighted spherical harmonic decomposition of the Weyl scalar ${\psi }_4$ representing outgoing radiation in the Kinnersley tetrad. We test our formula by measuring the radiated angular momentum from three simulations of nonspinning equal-mass–black-hole binaries with orbital angular momentum aligned along the $x$, $y$, and $z$ axes, respectively. We find that the radiated angular momentum agrees with the differences in the remnant horizon spins and the initial angular momentum for each system.