Strong foreground contamination in high resolution CMB data requires masking which introduces statistical anisotropies and renders a full maximum likelihood analysis numerically intractable. Standard analysis methods like the pseudo-$C_l$ framework lead to information loss due to estimator suboptimalities. We set out and validate a methodology for numerically efficient estimators for a masked sky that recover nearly as much information as a full maximum likelihood procedure. In addition to the standard pseudo-$C_l$ statistic, the approach introduces an augmented basis designed to account for the mode coupling due to the masking of the sky. We motivate the choice of this basis by describing the basic structure of the covariance matrix. We demonstrate that the augmented estimator can achieve near-optimal results in the presence of a WMAP-realistic mask.

The QCD phase diagram at densities relevant to neutron stars remains elusive, mainly due to the fermion-sign problem. At the same time, a plethora of possible phases has been predicted in models. Meanwhile ${\mathrm{G}}_2$-QCD, for which the $SU(3)$ gauge group of QCD is replaced by the exceptional Lie group ${\mathrm{G}}_2$, does not have a sign problem and can be simulated at such densities using standard lattice techniques. It thus provides benchmarks to models and functional continuum methods, and it serves to unravel the nature of possible phases of strongly interacting matter at high densities. Instrumental in understanding these phases is that ${\mathrm{G}}_2$-QCD has fermionic baryons, and that it can therefore sustain a baryonic Fermi surface. Because the baryon spectrum of ${\mathrm{G}}_2$-QCD also contains bosonic diquark and probably other more exotic states, it is important to understand this spectrum before one can disentangle the corresponding contributions to the baryon density. Here we present a first systematic classification of this spectrum. The qualitative features of this spectrum are reflected in our simulation results at different quark masses although our lattices are still rather coarse. This allows us to relate the mass hierarchy, ranging from scalar would-be-Goldstone bosons and intermediate vector bosons to the ${\mathrm{G}}_2$ nucleons and deltas, to individual structures observed in the total baryon density at finite chemical potential.

All current experiments searching for an electron electric dipole moment (EDM) $d_e$ are performed with atoms and diatomic molecules. Motivated by significant recent progress in searches for an EDM-type signal in diatomic molecules with an uncompensated electron spin, we provide an estimate for the expected signal in the Standard Model due to the Cabibbo-Kobayashi-Maskawa (CKM) phase. We find that the main contribution originates from the effective electron-nucleon operator $\overline{e}i{\gamma }_{5}e\overline{N}N$, induced by a combination of weak and electromagnetic interactions at $O(G_F^2{\alpha }^2)$, and not by the CKM-induced electron EDM itself. When the resulting atomic $P,T$-odd mixing is interpreted as an equivalent electron EDM, this estimate leads to the benchmark $d_e^{\text{equiv}}(\text{CKM})\sim {10}^{-38}e\mathrm{cm}$.

The recent discovery of a Higgs boson with mass of about 125 GeV, along with its striking similarity to the prediction from the standard model, informs and constrains many models of new physics. The Higgs mass exhausts one out of three input parameters of the minimal, five-dimensional version of universal extra dimension models, the other two parameters being the Kaluza-Klein (KK) scale and the cutoff scale of the theory. The presence of KK fermions with large coupling to the Higgs implies a short-lived electroweak vacuum, unless the cutoff scale is at most a few times higher than the KK mass scale, providing an additional tight constraint to the theory parameter space. Here, we focus on the lightest KK particle as a dark matter candidate, and investigate the regions of parameter space where such particle has a thermal relic density in accord with the cosmological dark matter density. We find the paradoxical result that, for low enough cutoff scales consistent with vacuum stability, larger than previously thought KK mass scales become preferred to explain the dark matter abundance in the Universe. We explain this phenomenon by pinpointing the additional particles which, at such low cutoffs, become close enough in mass to the dark matter candidate to coannihilate with it. We make predictions for both collider and direct dark matter searches that might soon close in on all viable theory parameter space.

We present a new clash-of-symmetries mechanism in the context of an intersecting domain-wall brane model in $5+1$-dimensional Minkowskian spacetime recently proposed by the authors. This new application of the Dvali—Shifman idea is designed for localizing gauge fields on a domain-wall intersection, and we employ it by adding a gauge group $G$ and giving the scalar fields which form lumplike profiles gauge charges. These fields in turn break $G$ to two different subgroups $H_1$ and $H_2$ respectively on each domain wall, and the gauge fields of these subgroups are taken to be localized to the respective walls by the confinement dynamics of $G$. There is then a further breaking on the domain-wall intersection to $H_1\cap H_2$, and gauge fields of this overlap group can then be localized to the intersection if they belong inside non-Abelian subgroups of both $H_1$ and $H_2$, which are spontaneously broken on the intersection and confining in the $4+1$-dimensional bulks of the respective domain-wall branes. This mechanism has some similarities to the clash-of-symmetries mechanism on a single domain wall, except that in this case $H_1$ and $H_2$ need not be isomorphic. We then give some interesting examples of the mechanism in an $SU(7)$ gauge theory, several of which result in the localization of the Standard Model gauge group.

We consider a class of leptogenesis models in which the lepton asymmetry arises from dark matter annihilation processes which violate $CP$ and lepton number. Importantly, a necessary one-loop contribution to the annihilation matrix element arises from absorptive final-state interactions. We elucidate the relationship between this one-loop contribution and the $CP$-violating phase. As we show, the branching fraction for dark matter annihilation to leptons may be small in these models, while still generating the necessary asymmetry.

We evaluate the ratio of the shear viscosity to the relaxation time of the shear current above but near the critical temperature $T_c$ in SU(3) gauge theory on the lattice. The ratio is related to Kubo’s canonical correlation of the energy-momentum tensor in Euclidean space with the relaxation-time approximation and an appropriate regularization. Using this relation, we evaluate the ratio on the lattice in Euclidean space. We obtain the ratio with reasonable statistics for the range of temperature $1.5\lesssim T/T_c\lesssim 4$. We find that the characteristic speed of the transverse plane wave propagating in a gluon medium $v_{\eta }$ is almost constant, $v_{\eta }^2\simeq 0.5$, for $T/T_c\gtrsim 1.5$, which ensures the causality in this mode in second-order dissipative hydrodynamics.

We present the determination of the interquark potential together with quark “kinetic mass” $m_Q$ from the equal-time $Q\overline{Q}$ Bethe-Salpeter amplitude in lattice QCD. Our approach allows us to calculate spin-dependent $Q\overline{Q}$ potentials, e.g., the spin-spin potential, as well. To investigate several systematic uncertainties on such $Q\overline{Q}$ potentials, we carry out lattice QCD simulations using quenched gauge configurations generated with the single plaquette gauge action with three different lattice spacings, $a\approx 0.093$, 0.068, and 0.047 fm, and two different physical volumes, $L\approx 2.2$ and 3.0 fm. For heavy quarks, we employ the relativistic heavy quark action, which can control large discretization errors introduced by large quark mass $m_Q$. The spin-independent central $Q\overline{Q}$ potential for the charmonium system yields the “Coulomb plus linear” behavior with good scaling and small volume dependence. We explore the quark mass dependence over the wide mass range from the charm to beyond the bottom region and then demonstrate that the spin-independent central $Q\overline{Q}$ potential in the $m_Q\to \infty$ limit is fairly consistent with the static $Q\overline{Q}$ potential obtained from Wilson loops. The spin-spin potential at finite quark mass provides a repulsive interaction with a finite range, which becomes narrower as the quark mass increases. We also discuss the applicability of the $1/m_Q$ expansion approach for the spin-spin potential.

We show how to avoid unnecessary and uncontrolled assumptions usually made in the literature about soft $SU(3)$ flavor symmetry breaking in determining the two-flavor nucleon matrix elements relevant for direct detection of weakly interacting massive particles (WIMPs). Based on $SU(2)$ chiral perturbation theory, we provide expressions for the proton and neutron scalar couplings $f_u^{p,n}$ and $f_d^{p,n}$ with the pion-nucleon $\sigma$ term as the only free parameter, which should be used in the analysis of direct detection experiments. This approach for the first time allows for an accurate assessment of hadronic uncertainties in spin-independent WIMP-nucleon scattering and for a reliable calculation of isospin-violating effects. We find that the traditional determinations of V$f_u^p-f_u^n$ and $f_d^p-f_d^n$ are off by a factor of 2.

The flavor mixing induced by the mismatched vector-isoscalar and vector-isovector interactions at finite baryon chemical potential $\mu$ and isospin chemical potential ${\mu }_I$ is demonstrated in the Nambu–Jona-Lasinio (NJL) model of QCD. The influence of this nonanomaly flavor mixing on the possible separate chiral transitions at nonzero ${\mu }_I$ is studied under the assumption of the effective restoration of the $U(1{)}_A$ symmetry. We find that for the weak isospin asymmetry, the two separate phase boundaries found previously can be converted into one only if the vector-isovector coupling $g_v^v$ is significantly stronger than the vector-isoscalar one $g_v^s$ without the axial anomaly. When the weak Kabayashi–Maskawa–’t Hooft interaction is included, we find that the separation of the chiral transition with two critical end points for the relatively strong isospin asymmetry can still be removed, owing to the vector interactions. In this case, it is not the vector coupling difference but the strength of $g_v^v$ which is crucial for the only phase boundary. We also point out that, in the NJL-type model with mismatched vector interactions, the recently proposed equivalence for chiral transitions at finite $\mu$ and ${\mu }_I$ does not hold, even at the mean field approximation.

The inclusion of higher-dimensional gauge invariant operators induces new Lorentz structures in Higgs couplings with electroweak gauge boson pairs. This in principle affects the kinematics of Higgs production and decay, thereby modifying the efficiencies of the experimental cuts compared to what simulations based on the standard model interactions yield. Taking some sample cases, we perform a rigorous analysis of how the efficiencies differ for various strengths of the additional operator vis-à-vis the standard model interactions, scanning over the values of both of them. While the response to cuts can be markedly different in some regions, we find that the sensitivity to new operator structures is relatively limited, so long as we remain confined to the $2\sigma$ regions around the best fit signal strengths measured at the Large Hadron Collider. We also show modifications to certain kinematical distributions including the new operators in the diphoton final state.

The recent results of the Planck experiment put a stringent constraint on the sum of the light neutrino masses, ${\mathrm{\Sigma }}_i{m}_i<0.23\mathrm{eV}$ (95% C.L.). On the other hand, two-zero Majorana mass matrix textures predict strong correlations among the atmospheric angle ${\sin }^2{\theta }_{23}$ and $\mathrm{\Sigma }$. We use the Planck result to show that, for the normal hierarchy case, the texture with vanishing (2, 2) and (3, 3) elements is ruled out at a high confidence level; in addition, we emphasize that a future measurement of the octant of ${\theta }_{23}$ (or the $1\sigma$ determination of it based on a recent fit to neutrino data) will put a severe constraint on the possible structure of the Majorana mass matrix. The implication of the above-mentioned correlations for neutrinoless double $\beta$ decay are also discussed, for both normal and inverted orderings.

We present some exact solutions of relativistic second order hydrodynamic equations in theories with conformal symmetry. Starting from a spherically expanding solution in ideal hydrodynamics, we take into account general conformal second order corrections and construct, for the first time, fully analytical axisymmetric solutions including the case with nonzero vorticity. These solutions are time reversible despite having a nonvanishing shear stress tensor, and provide a useful quantitative measure of the second order effects in relativistic hydrodynamics.

We study a novel non-Abelian matrix configuration of probe D-branes in ${\mathrm{AdS}}_5$. This configuration gives rise to a new D-brane phenomenon related to the known “Myers effect” in the context of holography. It is dual to a deformation of the field theory by a Wilson line threaded fermion bilinear. We study the two-point function of these short Wilson lines from both the non-Abelian Dirac-Born-Infeld action and a classical string world sheet calculation and identify the region where they agree. We also study a related configuration where the non-Abelian nature of the embedding functions is enhanced by a background flux as in the Myers effect.

The issue of electric charges in interaction with partially reflective surfaces is addressed by means of field theoretic methods. We propose an enlarged Maxwell Lagrangian, describing the electromagnetic field in the presence of a semitransparent surface, and its corresponding photon propagator is computed exactly. The amended Green function reduces to the one for a perfect conductor in the appropriate limit and leads to the interaction between charges and surfaces with varying degrees of transparency, featured by a phenomenological parameter. The interaction found via the image method is recovered, in the limiting case of a perfect mirror, as a testimony to the validity of the model.

Over the last three decades, entanglement entropy has been obtained for quantum fields propagating in Genus-0 topologies (spheres). For scalar fields propagating in these topologies, it has been shown that the entanglement entropy scales as area. In the last few years, nontrivial topologies are increasingly relevant for different areas. For instance, in describing quantum phases, it has been realized that long-range entangled states are described by topological order. If quantum entanglement can plausibly provide explanation for these, it is then imperative to obtain entanglement entropy in these topologies. In this work, using two different methods, we explicitly show that the entanglement entropy scales as area of the Genus-1 geometry.

We construct a noncommutative version of a general renormalizable SO(10) GUT with Higgses in the 210, $\overline{126}$, 45, 10 and 120 irreps of SO(10) and a Peccei-Quinn symmetry. Thus, we formulate the noncommutative counterpart of a nonsupersymmetric SO(10) GUT which has recently been shown to be consistent with all the physics below $M_{\mathrm{GUT}}$. The simplicity of our construction—the simplicity of the Yukawa terms, in particular—stems from the fact that the Higgses of our GUT can be viewed as elements of the Clifford algebra $\mathbb{C}{\mathrm{l}}_{10}(\mathbb{C})$; elements on which the SO(10) gauge transformations act by conjugation. The noncommutative GUT we build contains tree-level interactions among different Higgs species that are absent in their ordinary counterpart as they are forbidden by SO(10) and Lorentz invariance. The existence of these interactions helps to clearly distinguish noncommutative Minkowski space-time from ordinary Minkowski space-time.

We present a new unification of the electroweak and gravitational interactions based on joining the weak $SU(2)$ gauge fields with the left-handed part of the space-time connection, into a single gauge field valued in the complexification of the local Lorentz group. Hence, the weak interactions emerge as the right-handed chiral half of the space-time connection, which explains the chirality of the weak interaction. This is possible, because, as shown by Plebanski, Ashtekar, and others, the other chiral half of the space-time connection is enough to code the dynamics of the gravitational degrees of freedom. This unification is achieved within an extension of the Plebanski action previously proposed by one of us. The theory has two phases. A parity symmetric phase yields, as shown by Speziale, a bimetric theory with 8 degrees of freedom: the massless graviton, a massive spin-2 field and a scalar ghost. Because of the latter this phase is unstable. Parity is broken in a stable phase where the 8 degrees of freedom arrange themselves as the massless graviton coupled to an $SU(2)$ triplet of chirally coupled Yang-Mills fields. It is also shown that under this breaking a Dirac fermion expresses itself as a chiral neutrino paired with a scalar field with the quantum numbers of the Higgs.

Waveform templates are a powerful tool for extracting and characterizing gravitational wave signals, acting as highly restrictive priors on the signal morphologies that allow us to extract weak events buried deep in the instrumental noise. The templates map the waveform shapes to physical parameters, thus allowing us to produce posterior probability distributions for these parameters. However, there are attendant dangers in using highly restrictive signal priors. If strong field gravity is not accurately described by general relativity (GR), then using GR templates may result in fundamental bias in the recovered parameters, or even worse, a complete failure to detect signals. Here we study such dangers, concentrating on three distinct possibilities. First, we show that there exist modified theories compatible with all existing observations that would fail to be detected by the LIGO/Virgo network using searches based on GR templates, but which would be detected using a one parameter post-Einsteinian extension. Second, we study modified theories that produce departures from GR that turn on suddenly at a critical frequency, producing waveforms that do not directly fit into the simplest parametrized post-Einsteinian (ppE) scheme. We show that even the simplest ppE templates are still capable of picking up these strange signals and diagnosing a departure from GR. Third, we study whether using inspiral-only ppE waveforms for signals that include merger and ringdown can lead to problems in misidentifying a GR departure. We present a simple technique that allows us to self-consistently identify the inspiral portion of the signal, and thus remove these potential biases, allowing GR tests to be performed on higher mass signals that merge within the detector band. We close by studying a parametrized waveform model that may allow us to test GR using the full inspiral-merger-ringdown signal.

We discuss the ($2+1$)-dimensional parity-violating charged fluid on a finite cutoff surface ${\mathrm{\Sigma }}_c$, dual to the nondynamical and dynamical Chern-Simons (CS) modified gravities. Using the nonrelativistic long-wavelength expansion method, the field equations are solved up to $\mathcal{O}({\epsilon }^2)$ in the nondynamical model. It is shown that there exists nonvortical dual fluid with shear viscosity $\eta$ and Hall viscosity ${\eta }_A$ on the cutoff surface ${\mathrm{\Sigma }}_c$. The ratio of shear viscosity over entropy density $\eta /s$ of the fluid takes the universal value $1/4\pi$, while the ratio of Hall viscosity over entropy density ${\eta }_A/s$ depends on the ${\mathrm{\Sigma }}_c$ and black brane charge $q$. Moreover, the nonvortical dual fluid obeys the magnetohydrodynamic (MHD) equation. However, these kinematic viscosities $\nu$ and ${\nu }_A$ related to $\eta$ and ${\eta }_A$ do not appear in this MHD equation due to the constraint condition ${\tilde{\partial }}^2{\beta }_j=0$ for the ($2+1$)-dimensional dual fluid. Then, we extend our discussion to the dynamical CS modified gravity and show that the dual vortical fluid possesses another so-called Curl viscosity ${\zeta }_A$, whose ratio to entropy density ${\zeta }_A/s$ also depends on the ${\mathrm{\Sigma }}_c$ and $q$. Moreover, the value of $\eta /s$ still equals $1/4\pi$ and the result of ${\eta }_A/s$ agrees with the previous result under the probe limit of the pseudoscalar field at the infinite boundary in the charged black brane background for the dynamical CS modified gravity. This vortical dual fluid corresponds to the MHD turbulence equation in plasma physics.