We propose a model which accounts for the dynamical origin of the electroweak symmetry breaking (EWSB), directly linking to the mass generation of dark matter (DM) candidates and active neutrinos. The standard model (SM) is weakly charged under the $U(1{)}_{B-L}$ gauge symmetry, in conjunction with newly introduced three right-handed Majorana neutrinos and the $U(1{)}_{B-L}$ Higgs. The model is built on the classical scale invariance, that is dynamically broken by a new strongly coupled sector, that is called the hypercolor (HC) sector, which is also weakly coupled to the $U(1{)}_{B-L}$ gauge. At the HC strong scale, the simultaneous breaking of the EW and $U(1{)}_{B-L}$ gauge symmetries is triggered by dynamically induced multiple seesaw mechanisms, namely bosonic seesaw mechanisms. Thus, all of the origins of masses are provided singly by the HC dynamics: that is what we call the dynamical scalegenesis. We also find that a HC baryon, with a mass on the order of a few TeV, can be stabilized by the HC baryon number and the $U(1{)}_{B-L}$ charge, so identified as a DM candidate. The relic abundance of the HC-baryon DM can be produced dominantly via the bosonic-seesaw portal process, and the HC-baryon DM can be measured through the large magnetic moment coupling generated from the HC dynamics, or the $U(1{)}_{B-L}$-gauge boson portal in direct detection experiments.

We explore a scenario that dark matter is a boson condensate created by the misalignment mechanism, in which a spin 0 boson (an axionlike particle) and a spin 1 boson (the dark photon) are considered, respectively. We find that although the sub-MeV dark matter boson is extremely stable, the huge number of dark matter particles in a galaxy halo makes the decaying signal detectable. A galaxy halo is a large structure bounded by gravity with a typical $\sim 10^{12}$ solar mass, and the majority of its components are made of dark matter. For the axionlike particle case, it decays via $\varphi \to \gamma \gamma$, therefore the photon spectrum is monochromatic. For the dark photon case, it is a three body decay $A^{\prime }\to \gamma \gamma \gamma$. However, we find that the photon spectrum is heavily peaked at $M/2$ and thus can facilitate observation. We also suggest a physical explanation for the three body decay spectrum by comparing the physics in the decay of orthopositronium. In addition, for both cases, the decaying photon flux can be measured for some regions of parameter space using current technologies.

We present a supersymmetric (SUSY) model based on trinification $[\mathrm{SU}(3){]}^3$ and family $\mathrm{SU}(3{)}_{\mathrm{F}}$ symmetries embedded into a maximal subgroup of ${\mathrm{E}}_8$, where the sectors of light Higgs bosons and leptons are unified into a single chiral supermultiplet. The common origin of gauge trinification and of the family symmetry from ${\mathrm{E}}_8$ separates the model from other trinification-based GUTs, as it protects, in particular, the Standard Model fermions from gaining mass until the electroweak symmetry is broken. Furthermore, it allows us to break the trinification symmetry via vacuum expectation values in SU(3)-adjoint scalars down to a left-right symmetric theory. Simultaneously, it ensures the unification of the gauge and Yukawa couplings as well as proton stability. Although the low-energy regime (e.g., mass hierarchies in the scalar sector determined by a soft SUSY-breaking mechanism) is yet to be established, these features are one key to revive the once very popular trinification-based GUTs.

We present results for the (color)magnetic and (color)electric screening masses of the quark-gluon plasma in the presence of an external magnetic field. The screening masses are extracted from the correlators of Polyakov loops, determined by lattice QCD simulations at the physical point. We explore temperatures in the range $200\mathrm{MeV}\lesssim T\lesssim 330\mathrm{MeV}$ and magnetic field intensities up to $|e|B\sim 1.3{\mathrm{GeV}}^2$. We find that both screening masses are increasing functions of the magnetic field and that the dependence on $B$ becomes weaker for larger temperatures. In the case of the magnetic screening mass, a slight anisotropy is also observable.

Properties of the wave function equivalent potentials introduced by the HAL QCD collaboration are studied in a nonrelativistic coupled-channel model. The derivative expansion is generalized, and then applied to the energy-independent and nonlocal potentials. The expansion coefficients are determined from analytic solutions to the Nambu-Bethe-Salpeter wave functions. The scattering phase shifts computed from these potentials are compared with the exact values to examine the convergence of the expansion. It is confirmed that the generalized derivative expansion converges in terms of the scattering phase shift rather than the functional structure of the non-local potentials. It is also found that the convergence can be improved by tuning either the choice of interpolating fields or expansion scale in the generalized derivative expansion.

Transition form factors $F_{P{\gamma }^{*}{\gamma }^{(*)}}$ of pseudoscalar mesons are studied within the framework of the domain model of confinement, chiral symmetry breaking, and hadronization. In this model the QCD vacuum is described by the statistical ensemble of domain wall networks which represents the almost everywhere homogeneous Abelian (anti-)self-dual gluon field configurations. Calculations of the form factors are performed consistently with mass spectra of mesons, their weak and strong decay constants. Influence of the nonperturbative intermediate range gluon fields on behavior of pion transition form factor at large $Q^2$ is of particular interest. It is found that $Q^2{F}_{\pi {\gamma }^{*}\gamma }(Q^2)$ approaches a constant value at asymptotically large $Q^2$. However, due to the contribution of confining gluon fields this limit exceeds the standard factorization bound, though the form factor complies with Belle data more likely than with BABAR ones. At the same time the generally accepted factorization bound is shown to be satisfied for the case of the symmetric kinematics, $Q^2{F}_{P{\gamma }^{*}{\gamma }^{*}}(Q^2)$. Peculiarities of description of $\eta$, ${\eta }^{\prime }$, and ${\eta }_c$ form factors within the model are discussed in detail.

The production of the vector meson pairs $B_s^{*}{\overline{B}}_s^{*}$ in the $e^{+}{e}^{-}$ annihilation is generally contributed by two $P$ wave amplitudes with different total spin $S$ of the mesons, $S=0$ and $S=2$, and also by an $F$ wave amplitude. Belle has recently reported a study of the available data at the energy of the $\mathrm{\Upsilon }(5S)$ peak in terms of the two $P$ wave contributions only. It is argued here that, although at this energy the $F$ wave should be quite suppressed, especially for the strange-bottom vector mesons, the particular studied angular distribution is very sensitive to a presence of even a small $F$ wave amplitude due to a significant interference with the dominant $S=2$ $P$ wave. Thus, the available data are not conclusive with regard to the partial wave structure of the production amplitude. Additional angular correlations that can be measured for a full amplitude analysis of the production process are discussed.

We revisited the solution of a linearized form of the leading-order Balitsky-Kovchegov equation (linear in the $S$-matrix for dipole-nucleus scattering). Here we adopted a dipole transverse-width-dependent cutoff in order to regulate the dipole integral. We also have taken care of all the higher-order terms (higher order in the cutoff) that have been reasonably neglected before. The solution reproduces both the McLerran-Venugopalan-type initial condition (Gaussian in the scaling variable) and the Levin-Tuchin solution (Gaussian in the logarithm of scaling variable) in the appropriate limits. It also connects these two opposite limits smoothly with better accuracy for sets of rescaled rapidity when compared to numerical solutions of the full leading-order Balitsky-Kovchegov equation.

Photoproduction of $K^{*}$ vector meson off the nucleon is investigated within the Regge framework where the electromagnetic vertex of $\gamma K^{*}{K}^{*}$ fully takes into account the magnetic dipole and electric quadrupole moments in addition to the electric charge of the spin-1 $K^{*}$ vector meson. The $t$-channel $K^{*}(892)$, $K(494)$, and $\kappa (800)$ meson exchanges are considered for the analysis of the production mechanism. The rapid decrease of the cross sections for the $\gamma p\to K^{*+}\mathrm{\Lambda }$ reaction experimentally observed beyond the resonance region is well reproduced by the dominance of the exchange of $K$-meson trajectory. The total cross section for the $\gamma n\to K^{*0}\mathrm{\Lambda }$ reaction is predicted to be about twice that of the $\gamma p\to K^{*+}\mathrm{\Lambda }$ reaction. The role of the $K^{*}$ electromagnetic multipole moments is studied through the analysis of total and differential cross sections and model predictions are presented for the polarization asymmetries of the photon, recoiled $\mathrm{\Lambda }$, and parity asymmetry. We suggest measuring the photon polarization asymmetry as a tool to identify the role of the magnetic dipole and electric quadrupole moments of the $K^{*}$ vector meson.

The $K_S^0-K_L^0$ asymmetries in the $D$-meson decays, induced by the interference between the Cabibbo-favored and the doubly Cabibbo-suppressed amplitudes, can help to understand the dynamics of charm decays. All possible processes of two-body nonleptonic $D$ decays into one neutral kaon and another pseudoscalar or vector meson are considered. We study the $K_S^0-K_L^0$ asymmetries and the branching fractions of corresponding processes in the factorization-assisted topological-amplitude approach in which significant flavor $SU(3)$ symmetry breaking effects are included. The branching fractions of the $K_L^0$ modes are predicted. It is first found that the $K_S^0-K_L^0$ asymmetries in the $D^0$-meson decays are shifted by the $D^0-{\overline{D}}^0$ mixing parameter $y_D\simeq 0.006$, to be $0.113\pm 0.001$ for all the relevant $D^0$ decay modes. Our results on $K_S^0-K_L^0$ asymmetries are consistent with the current data and could be tested by experiments in the future.

Visinelli and Gondolo [Phys. Rev. D 91, 083526 (2015)., hereafter VG15] derived analytic expressions for the evolution of the dark matter temperature in a generic cosmological model. They then calculated the dark matter kinetic decoupling temperature $T_{\mathrm{kd}}$ and compared their results to the Gelmini and Gondolo [J. Cosmol. Astropart. Phys. 10 (2008) 002., hereafter GG08] calculation of $T_{\mathrm{kd}}$ in an early matter-dominated era (EMDE), which occurs when the Universe is dominated by either a decaying oscillating scalar field or a semistable massive particle before Big Bang nucleosynthesis. VG15 found that dark matter decouples at a lower temperature in an EMDE than it would in a radiation-dominated era, while GG08 found that dark matter decouples at a higher temperature in an EMDE than it would in a radiation-dominated era. VG15 attributed this discrepancy to the presence of a matching constant that ensures that the dark matter temperature is continuous during the transition from the EMDE to the subsequent radiation-dominated era and concluded that the GG08 result is incorrect. We show that the disparity is due to the fact that VG15 compared $T_{\mathrm{kd}}$ in an EMDE to the decoupling temperature in a radiation-dominated universe that would result in the same dark matter temperature at late times. Since decoupling during an EMDE leaves the dark matter colder than it would be if it decoupled during radiation domination, this temperature is much higher than $T_{\mathrm{kd}}$ in a standard thermal history, which is indeed lower than $T_{\mathrm{kd}}$ in an EMDE, as stated by GG08.

In loop quantum cosmology, one has to make a choice of SU(2) irreducible representation in which to compute holonomies and regularize the curvature of the connection. The systematic choice made in the literature is to work in the fundamental representation, and very little is known about the physics associated with higher spin labels. This constitutes an ambiguity of which the understanding, we believe, is fundamental for connecting loop quantum cosmology to full theories of quantum gravity like loop quantum gravity, its spin foam formulation, or cosmological group field theory. We take a step in this direction by providing here a new closed formula for the Hamiltonian of flat Friedmann-Lemaître-Robertson-Walker models regularized in a representation of arbitrary spin. This expression is furthermore polynomial in the basic variables which correspond to well-defined operators in the quantum theory, takes into account the so-called inverse-volume corrections, and treats in a unified way two different regularization schemes for the curvature. After studying the effective classical dynamics corresponding to single and multiple-spin Hamiltonians, we study the behavior of the critical density when the number of representations is increased and the stability of the difference equations in the quantum theory.

We present the first results on the third order corrections to on-shell form factor (FF) of the Konishi operator in $\mathcal{N}=4$ supersymmetric Yang-Mills theory using Feynman diagrammatic approach in modified dimensional reduction ($\overline{DR}$) scheme. We show that it satisfies the KG equation in $\overline{DR}$ scheme while the result obtained in four dimensional helicity (FDH) scheme needs to be suitably modified not only to satisfy the KG equation but also to get the correct ultraviolet (UV) anomalous dimensions. We find that the cusp, soft and collinear anomalous dimensions obtained to third order are same as those of the FF of the half-BPS operator confirming the universality of the infrared (IR) structures of on-shell form factors. In addition, the highest transcendental terms of the FF of the Konishi operator are identical to those of half-BPS operator indicating the probable existence of deeper structure of the on-shell FF. We also confirm the UV anomalous dimensions of the Konishi operator up to third order providing a consistency check on the both UV and universal IR structures in $\mathcal{N}=4$.

In this paper, we consider the $\beta$ function at one-loop approximation for noncommutative scalar QED. The renormalization of the full theory, including the basic vertices, and the renormalization group equation are fully established. Next, the complete set of the one-loop diagrams corresponding to the first-order radiative corrections to the basic functions is considered: gauge, charged scalar and ghost fields self-energies, and three- and four-point vertex functions $⟨{\varphi }^{†}\varphi A⟩$, $⟨{\varphi }^{†}\varphi AA⟩$, and $⟨{\varphi }^{†}\varphi {\varphi }^{†}\varphi ⟩$, respectively. We pay special attention to the noncommutative contributions to the renormalization constants. To conclude, the one-loop $\beta$ function of noncommutative scalar QED is then computed and comparison to known results is presented.

We find that, for the near horizon static isotropic metric, all of the massless field equations of the spin $\le 2$ have the same characteristic: they can be reduced to the Fuchsian-type equation with three regular singular points. Three general solutions, corresponding to different parameter values, are obtained. Two of the solutions have discrete imaginary frequencies. Based on the results above, we obtain exact formulas for the quasinormal modes of the Rindler-type spacetime. We also derive an elegant wave equation, which is the fundamental formula of the perturbation theory for general static spherically symmetric spacetime.

We study how a strong gravity affects the equation of state of matter. For this purpose, we employ a canonical ensemble of classical monoatomic ideal gas inside a box in Rindler spacetime. The total energy decreases monotonically with the increase of the external gravity, representing its attractiveness. It is, however, bounded below, which is different from the Newtonian gravity case. As for the entropy, it decreases with the external gravity in the Newtonian regime. However, in the presence of strong gravity or ultrarelativistic high temperature, the entropy increases with the gravity. This result can be a resolution of the negative entropy problem of the ideal gas in Newtonian gravity. In the presence of strong gravity, the bottom of the box is very close to the event horizon of Rindler spacetime, mimicking a black hole, and the gas behaves as if it is on an effective two-dimensional surface located at the bottom of the box. Investigating the equation of state in the strong gravity regime, the temperature of the system is found to be not a free parameter but to approach a fixed value proportional to the external gravity, which is reminiscent of the Unruh temperature.

We construct a scalar polynomial curvature invariant that transforms covariantly under a conformal transformation from any spherically symmetric metric. This invariant has the additional property that it vanishes on the event horizon of any black hole that is conformal to a static spherical metric.

If a small “particle” of mass $\mu M$ (with $\mu \ll 1$) orbits a black hole of mass $M$, the leading-order radiation-reaction effect is an $\mathcal{O}({\mu }^2)$ “self-force” acting on the particle, with a corresponding $\mathcal{O}(\mu )$ “self-acceleration” of the particle away from a geodesic. Such “extreme-mass-ratio inspiral” systems are likely to be important gravitational-wave sources for future space-based gravitational-wave detectors. Here we consider the “toy model” problem of computing the self-force for a scalar-field particle on a bound eccentric orbit in Kerr spacetime. We use the Barack-Golbourn-Vega-Detweiler effective-source regularization with a 4th-order puncture field, followed by an $e^{im\varphi }$ (“$m$-mode”) Fourier decomposition and a separate time-domain numerical evolution in $2+1$ dimensions for each $m$. We introduce a finite worldtube that surrounds the particle worldline and define our evolution equations in a piecewise manner so that the effective source is only used within the worldtube. Viewed as a spatial region, the worldtube moves to follow the particle’s orbital motion. We use slices of constant Boyer-Lindquist time in the region of the particle’s motion, deformed to be asymptotically hyperboloidal and compactified near the horizon and ${\mathcal{J}}^{+}$. Our numerical evolution uses Berger-Oliger mesh refinement with 4th-order finite differencing in space and time. Our computational scheme allows computation for highly eccentric orbits and should be generalizable to orbital evolution in the future. Our present implementation is restricted to equatorial geodesic orbits, but this restriction is not fundamental. We present numerical results for a number of test cases with orbital eccentricities as high as 0.98. In some cases we find large oscillations (“wiggles”) in the self-force on the outgoing leg of the orbit shortly after periastron passage; these appear to be caused by the passage of the orbit through the strong-field region close to the background Kerr black hole.

We study the quasilocal energy (QLE) and the surface geometry for Kerr spacetime in the Boyer-Lindquist coordinates without taking the slow rotation approximation. We also consider in the region $r\le 2m$, which is inside the ergosphere. For a certain region, $r>r_k(a)$, the Gaussian curvature of the surface with constant $t$, $r$ is positive, and for $r>\sqrt{3}a$ the critical value of the QLE is positive. We found that the three curves: the outer horizon $r=r_{+}(a)$, $r=r_k(a)$ and $r=\sqrt{3}a$ intersect at the point $a=\sqrt{3}m/2$, which is the limit for the horizon to be isometrically embedded into ${\mathbb{R}}^3$. The numerical result indicates that the Kerr QLE is monotonically decreasing to the ADM $m$ from the region inside the ergosphere to large $r$. Based on the second law of black hole dynamics, the QLE is increasing with respect to the irreducible mass $M_{\mathrm{ir}}$. From the results of Chen-Wang-Yau, we conclude that in a certain region, $r>r_h(a)$, the critical value of the Kerr QLE is a global minimum.

We discuss the propagation of electromagnetic (EM) waves in the post-Newtonian approximation of the general theory of relativity. We consider diffraction of EM waves in the static gravitational field of a massive monopole. We develop a wave-theoretical description of the solar gravitational lens (SGL) and show that with its enormous magnifying power of $\sim {10}^{11}$ (for $\lambda =1\mu \mathrm{m}$) and angular resolution of $\lesssim {10}^{-10}\mathrm{arcsec}$, the SGL may be used for direct megapixel imaging of an exoplanet.