We analyze the impact of the recent HERA Run $\mathrm{I}+\mathrm{II}$ combination of inclusive deep inelastic scattering cross-section data on the CT14 global analysis of parton distribution functions (PDFs). New PDFs at next-to-leading order and next-to-next-to-leading order, called ${\mathrm{CT}14}_{\mathrm{HERA}2}$, are obtained by a refit of the CT14 data ensembles, in which the HERA Run I combined measurements are replaced by the new HERA Run $\mathrm{I}+\mathrm{II}$ combination. The CT14 functional parametrization of PDFs is flexible enough to allow good descriptions of different flavor combinations, so we use the same parametrization for ${\mathrm{CT}14}_{\mathrm{HERA}2}$ but with an additional shape parameter for describing the strange quark PDF. We find that the HERA $\mathrm{I}+\mathrm{II}$ data can be fit reasonably well, and both CT14 and ${\mathrm{CT}14}_{\mathrm{HERA}2}$ PDFs can describe equally well the non-HERA data included in our global analysis. Because the CT14 and ${\mathrm{CT}14}_{\mathrm{HERA}2}$ PDFs agree well within the PDF errors, we continue to recommend CT14 PDFs for the analysis of LHC Run 2 experiments.

In the framework of the color-magnetic interaction, we have systematically studied the mass splittings of the possible hidden-charm pentaquarks $qqqc\overline{c}$ ($q=u$, $d$, $s$) where the three light quarks are in a color-octet state. We find that (i) the LHCb $P_c$ states fall in the mass region of the studied system, (ii) most pentaquarks should be broad states since their $S$-wave open-charm decays are allowed while the lowest state is the $J^P={\frac{1}{2}}^{-}$ $\mathrm{\Lambda }$-like pentaquark with probably the suppressed ${\eta }_c\mathrm{\Lambda }$ decay mode only, and (iii) the $J^P={\frac{5}{2}}^{-}$ states do not decay through the $S$ wave and their widths are not so broad. The masses and widths of the two LHCb $P_c$ baryons are compatible with such pentaquark states. We also explore the hidden-bottom and $B_c$-like partners of the hidden-charm states and find the possible existence of the pentaquarks which are lower than the relevant hadronic molecules.

In a ($2+1$)-dimensional spacetime with a negative cosmological constant, the thermodynamics and the entropy of an extremal rotating thin shell, i.e., an extremal rotating ring, are investigated. The outer and inner regions with respect to the shell are taken to be the Bañados-Teitelbom-Zanelli (BTZ) spacetime and the vacuum ground state anti-de Sitter spacetime, respectively. By applying the first law of thermodynamics to the extremal thin shell, one shows that the entropy of the shell is an arbitrary well-behaved function of the gravitational area $A_{+}$ alone, $S=S(A_{+})$. When the thin shell approaches its own gravitational radius $r_{+}$ and turns into an extremal rotating BTZ black hole, it is found that the entropy of the spacetime remains such a function of $A_{+}$, both when the local temperature of the shell at the gravitational radius is zero and nonzero. It is thus vindicated by this analysis that extremal black holes, here extremal BTZ black holes, have different properties from the corresponding nonextremal black holes, which have a definite entropy, the Bekenstein-Hawking entropy $S(A_{+})=\frac{A_{+}}{4G}$, where $G$ is the gravitational constant. It is argued that for extremal black holes, in particular for extremal BTZ black holes, one should set $0\le S(A_{+})\le \frac{A_{+}}{4G}$; i.e., the extremal black hole entropy has values in between zero and the maximum Bekenstein-Hawking entropy $\frac{A_{+}}{4G}$. Thus, rather than having just two entropies for extremal black holes, as previous results have debated, namely, 0 and $\frac{A_{+}}{4G}$, it is shown here that extremal black holes, in particular extremal BTZ black holes, may have a continuous range of entropies, limited by precisely those two entropies. Surely, the entropy that a particular extremal black hole picks must depend on past processes, notably on how it was formed. A remarkable relation between the third law of thermodynamics and the impossibility for a massive body to reach the velocity of light is also found. In addition, in the procedure, it becomes clear that there are two distinct angular velocities for the shell, the mechanical and thermodynamic angular velocities. We comment on the relationship between these two velocities. In passing, we clarify, for a static spacetime with a thermal shell, the meaning of the Tolman temperature formula at a generic radius and at the shell.

Using our recently developed relativistic three-particle quantization condition [Phys. Rev. D 90, 116003 (2014); Phys. Rev. D 92, 114509 (2015)], we study the finite-volume energy shift of a spin-zero three-particle bound state. We reproduce the result obtained using nonrelativistic quantum mechanics by Meißner et al. in [Phys. Rev. Lett. 114, 091602 (2015)] and generalize the result to a moving frame.

We clarify the relation between noncommutative spacetimes and multifractional geometries, two quantum-gravity-related approaches where the fundamental description of spacetime is not given by a classical smooth geometry. Despite their different conceptual premises and mathematical formalisms, both research programs allow for the spacetime dimension to vary with the probed scale. This feature and other similarities led to ask whether there is a duality between these two independent proposals. In the absence of curvature and comparing the symmetries of both position and momentum space, we show that $\kappa$-Minkowski spacetime and the commutative multifractional theory with $q$-derivatives are physically inequivalent but they admit several contact points that allow one to describe certain aspects of $\kappa$-Minkowski noncommutative geometry as a multifractional theory and vice versa. Contrary to previous literature, this result holds without assuming any specific measure for $\kappa$-Minkowski. More generally, no well-defined $\star$-product can be constructed from the $q$-theory, although the latter does admit a natural noncommutative extension with a given deformed Poincaré algebra. A similar no-go theorem may be valid for all multiscale theories with factorizable measures. Turning gravity on, we write the algebras of gravitational first-class constraints in the multifractional theories with $q$- and weighted derivatives and discuss their differences with respect to the deformed algebras of $\kappa$-Minkowski spacetime and of loop quantum gravity.

Isolated objects in asymptotically flat spacetimes in general relativity are characterized by their conserved charges associated with the Bondi-Metzner-Sachs (BMS) group. These charges include total energy, linear momentum, intrinsic angular momentum and center-of-mass location, and, in addition, an infinite number of supermomentum charges associated with supertranslations. Recently, it has been suggested that the BMS symmetry algebra should be enlarged to include an infinite number of additional symmetries known as super-rotations. We show that the corresponding charges are finite and well defined, and can be divided into electric parity “super center-of-mass” charges and magnetic parity “superspin” charges. The supermomentum charges are associated with ordinary gravitational-wave memory, and the super center-of-mass charges are associated with total (ordinary plus null) gravitational-wave memory, in the terminology of Bieri and Garfinkle. Superspin charges are associated with the ordinary piece of spin memory. Some of these charges can give rise to black hole hair, as described by Strominger and Zhiboedov. We clarify how this hair evades the no-hair theorems.

Gravitational waves emitted during the coalescence of binary neutron star systems are self-calibrating signals. As such, they can provide a direct measurement of the luminosity distance to a source without the need for a cross-calibrated cosmic distance-scale ladder. In general, however, the corresponding redshift measurement needs to be obtained via electromagnetic observations since it is totally degenerate with the total mass of the system. Nevertheless, Fisher matrix studies have shown that, if information about the equation of state of the neutron stars is available, it is possible to extract redshift information from the gravitational wave signal alone. Therefore, measuring the cosmological parameters in pure gravitational-wave fashion is possible. Furthermore, the huge number of sources potentially observable by the Einstein Telescope has led to speculations that the gravitational wave measurement is potentially competitive with traditional methods. The Einstein Telescope is a conceptual study for a third generation gravitational wave detector which is designed to yield $10^3–10^7$ detections of binary neutron star systems per year. This study presents the first Bayesian investigation of the accuracy with which the cosmological parameters can be measured using information coming only from the gravitational wave observations of binary neutron star systems by the Einstein Telescope. We find, by direct simulation of $10^3$ detections of binary neutron stars, that, within our simplifying assumptions, $H_0$, ${\mathrm{\Omega }}_m$, ${\mathrm{\Omega }}_{\mathrm{\Lambda }}$, $w_0$ and $w_1$ can be measured at the 95% level with an accuracy of $\sim 8\%$, 65%, 39%, 80% and 90%, respectively. We also find, by extrapolation, that a measurement accuracy comparable with current measurements by Planck is possible if the number of gravitational wave events observed is $O(10^{6–7})$. We conclude that, while not competitive with electromagnetic missions in terms of significant digits, gravitational waves alone are capable of providing a complementary determination of the dynamics of the Universe.

We study the nonlinear $E$-mode clustering in Lagrangian space by using large scale structure $N$-body simulations and use the displacement field information in Lagrangian space to recover the primordial linear density field. We find that, compared to Eulerian nonlinear density fields, the $E$-mode displacement fields in Lagrangian space improves the cross-correlation scale $k$ with initial density field by a factor of 6–7, containing 2 orders of magnitude more primordial information. This illustrates ability of potential density reconstruction algorithms, to improve the baryonic acoustic oscillation measurements from current and future large scale structure surveys.

Flavor symmetries à la Froggatt-Nielsen provide a compelling way to explain the hierarchies of fermionic masses and mixing angles in the Yukawa sector. In supersymmetric (SUSY) extensions of the Standard Model where the mediation of SUSY breaking occurs at scales larger than the breaking of flavor, this symmetry must be respected not only by the Yukawas of the superpotential but also by the soft-breaking masses and trilinear terms. In this work we show that contrary to naive expectations, even starting with completely flavor blind soft breaking in the full theory at high scales, the low-energy sfermion mass matrices and trilinear terms of the effective theory, obtained upon integrating out the heavy mediator fields, are strongly nonuniversal. We explore the phenomenology of these SUSY flavor models after the latest LHC searches for new physics.

Four-dimensional manifolds with changing signature are obtained by taking the large $N$ limit of fuzzy $C{P}^2$ solutions to a Lorentzian matrix model. The regions of Lorentzian signature give toy models of closed universes which exhibit cosmological singularities. These singularities are resolved at finite $N$, as the underlying $C{P}^2$ solutions are expressed in terms of finite matrix elements.

Motivated by the goal for high accuracy modeling of gravitational radiation emitted by isolated systems, recently, there has been renewed interest in the numerical solution of the hyperboloidal initial value problem for Einstein’s field equations in which the outer boundary of the numerical grid is placed at null infinity. In this article, we numerically implement the tetrad-based approach presented by Bardeen, Sarbach, and Buchman [Phys. Rev. D 83, 104045 (2011)] for a spherically symmetric, minimally coupled, self-gravitating scalar field. When this field is massless, the evolution system reduces to a regular, first-order symmetric hyperbolic system of equations for the conformally rescaled scalar field which is coupled to a set of singular elliptic constraints for the metric coefficients. We show how to solve this system based on a numerical finite-difference approximation, obtaining stable numerical evolutions for initial black hole configurations which are surrounded by a spherical shell of scalar field, part of which disperses to infinity and part of which is accreted by the black hole. As a nontrivial test, we study the tail decay of the scalar field along different curves, including one along the marginally trapped tube, one describing the world line of a timelike observer at a finite radius outside the horizon, and one corresponding to a generator of null infinity. Our results are in perfect agreement with the usual power-law decay discussed in previous work. This article also contains a detailed analysis for the asymptotic behavior and regularity of the lapse, conformal factor, extrinsic curvature and the Misner-Sharp mass function along constant mean curvature slices.

The separation of quark and gluon initiated jets can be an important way to improve the sensitivity in searches for new physics or in measurements of Higgs boson properties. We present a simplified version of the shower deconstruction approach as a novel observable for quark-gluon tagging. Assuming topoclusterlike objects as input, we compare our observable with energy correlation functions and find a favorable performance for a large variety of jet definitions. We address the issue of infrared sensitivity of quark-gluon discrimination. When this approach is applied to dark matter searches in monojet final states, limitations from small signal-to-background ratios can be overcome. We also show that quark-gluon tagging is an alternative way of separating weak boson from gluon-fusion production in the process $p+p\to H+\text{jet}+\text{jet}+X$.

We quantize the moduli space of supersymmetric microstates describing four-dimensional black holes with ${\mathrm{AdS}}_2\times {\mathrm{S}}^2$ asymptotics. To acquire the commutation relations of quantization, we find the symplectic form that is imposed in the Type IIB supergravity and defined in the space of solutions parametrized by one complex harmonic function in ${\mathbf{R}}^3$ with sources distributed along closed curves.

We renormalize the six-dimensional cubic theory with an $O(N)\times O(m)$ symmetry at three loops in the modified minimal subtraction ($\overline{\mathrm{MS}}$) scheme. The theory lies in the same universality class as the four-dimensional Landau-Ginzburg-Wilson model. As a check we show that the critical exponents derived from the three-loop renormalization group functions at the Wilson-Fisher fixed point are in agreement with the large $N$ $d$-dimensional critical exponents of the underlying universal theory. Having established this connection we analyze the fixed point structure of the perturbative renormalization group functions to estimate the location of the conformal window of the $O(N)\times O(2)$ model.

We discuss the effects of a direct coupling between a Lorentz-violating rank-two antisymmetric tensor field and the Maxwell field. Two possible couplings are considered, which can be distinguished by whether or not they lead to vacuum birefringence. In both cases, the magnitude of the field components and the coupling coefficient can be bounded by observational constraints. For light propagating in the presence of a topological defect solution, both couplings lead to the deflection of light rays; however, these angular deflections can be expected to be extremely small: ${10}^{-9}$ arcseconds for the nonbirefringent coupling, and no more than ${10}^{-26}$ arcseconds for the birefringent coupling. We discuss the plausibility of this phenomenon as a method for detection of these monopoles.

We present a deformation of the action principle for a free tensor field of mixed symmetry (2, 1)—the Curtright action, a dual formulation of five-dimensional linearized gravity. It is constructed as the dual theory of the Einstein-Hilbert action linearized around a de Sitter background, and its derivation relies on the use of the two-potential formalism as an intermediate step. The resulting action principle is spatially nonlocal and space-time covariance is not manifest, thus overcoming previous no-go results.

We present a time domain waveform model that describes the inspiral, merger and ringdown of compact binary systems whose components are nonspinning, and which evolve on orbits with low to moderate eccentricity. The inspiral evolution is described using third-order post-Newtonian equations both for the equations of motion of the binary, and its far-zone radiation field. This latter component also includes instantaneous, tails and tails-of-tails contributions, and a contribution due to nonlinear memory. This framework reduces to the post-Newtonian approximant TaylorT4 at third post-Newtonian order in the zero-eccentricity limit. To improve phase accuracy, we also incorporate higher-order post-Newtonian corrections for the energy flux of quasicircular binaries and gravitational self-force corrections to the binding energy of compact binaries. This enhanced prescription for the inspiral evolution is combined with a fully analytical prescription for the merger-ringdown evolution constructed using a catalog of numerical relativity simulations. We show that this inspiral-merger-ringdown waveform model reproduces the effective-one-body model of Ref. [Y. Pan et al., Phys. Rev. D 89, 061501 (2014).] for quasicircular black hole binaries with mass ratios between 1 to 15 in the zero-eccentricity limit over a wide range of the parameter space under consideration. Using a set of eccentric numerical relativity simulations, not used during calibration, we show that our new eccentric model reproduces the true features of eccentric compact binary coalescence throughout merger. We use this model to show that the gravitational-wave transients GW150914 and GW151226 can be effectively recovered with template banks of quasicircular, spin-aligned waveforms if the eccentricity $e_0$ of these systems when they enter the aLIGO band at a gravitational-wave frequency of 14 Hz satisfies $e_0^{\mathrm{GW}150914}\le 0.15$ and $e_0^{\mathrm{GW}151226}\le 0.1$. We also find that varying the spin combinations of the quasicircular, spin-aligned template waveforms does not improve the recovery of nonspinning, eccentric signals when $e_0\ge 0.1$. This suggests that these two signal manifolds are predominantly orthogonal.