We study cosmological models described by a single real scalar field. We work within the first-order framework, and we show how the first-order equations simplify the investigation, leading to a direct search of twinlike theories. The procedure is used to introduce distinct models that support the same first-order equations, with the very same energy densities and pressure in flat spacetime. The presence of curvature forbids the construction of twinlike models in the cosmological scenario here investigated.

We study Casimir interactions between cylinders in thermal nonequilibrium, where the objects as well as the environment are held at different temperatures. We provide the general formula for the force, in a one reflection approximation, for cylinders of arbitrary radii and optical properties. As is the case for equilibrium, we find that the force for optically diluted cylinders can be obtained by appropriate summation of the corresponding result for spheres. We find that the nonequilibrium forces are generally larger than their equilibrium counterpart at separations greater than the thermal wavelength. They may also exhibit oscillations as function of separation, leading to stable points of zero net force. These effects are particularly pronounced for thin conducting cylinders (e.g. 40 nm diameter nanowires of tungsten) due to their large emissivity.

We consider a quantum field which is in a Hartle-Hawking state propagating in a general spherically symmetric black hole space-time. We make use of uniform approximations to the radial equation to calculate the components of the stress tensor, renormalized using the Hadamard form of the Green’s function, on the horizons of this space-time. We then specialize these results to the case of the “lukewarm” Reissner-Nordstrom–de Sitter black hole and derive some conditions on the stress tensor for the regularity of the Hartle-Hawking state.

We discuss an ambiguity in the one-loop effective action of massive fields which takes place in massive fermionic theories. The universality of logarithmic UV divergences in different space-time dimensions leads to the nonuniversality of the finite part of effective action, which can be called the nonlocal multiplicative anomaly. The general criteria of existence of this phenomena are formulated and applied to fermionic operators with different external fields.

We improve the numerical kludge waveform model introduced in Huerta and Gair (2011) [E. A. Huerta and J. R. Gair, Phys. Rev. D 84, 064023 (2011).] in two ways. We extend the equations of motion for spinning black hole binaries derived by Saijo et al. [M. Saijo, K. Maeda, M. Shibata, and Y. Mino, Phys. Rev. D 58, 064005 (1998).] using spin-orbit and spin-spin couplings taken from perturbative and post-Newtonian (PN) calculations at the highest order available. We also include first-order conservative self-force corrections for spin-orbit and spin-spin couplings, which are derived by comparison to PN results. We generate the inspiral evolution using fluxes that include the most recent calculations of small body spin corrections, spin-spin, and spin-orbit couplings and higher-order fits to solutions of the Teukolsky equation. Using a simplified version of this model in [E. A. Huerta and J. R. Gair, Phys. Rev. D 84, 064023 (2011).], we found that small body spin effects could be measured through gravitational-wave observations from intermediate-mass-ratio inspirals (IMRIs) with mass ratio $\eta \gtrsim {10}^{-3}$, when both binary components are rapidly rotating. In this paper, we present results of Monte Carlo simulations of parameter-estimation errors to study in detail how the spin of the small/big body affects parameter measurement using a variety of mass and spin combinations for typical IMRI sources. We have found that for IMRI events involving a moderately rotating intermediate-mass black hole (IMBH) of mass ${10}^4{M}_{\odot }$ and a rapidly rotating central supermassive black hole (SMBH) of mass ${10}^6{M}_{\odot }$, gravitational wave observations made with LISA at a signal-to-noise ratio of 1000 should be able to determine the inspiralling IMBH mass, the central SMBH mass, the SMBH spin magnitude, and the IMBH spin magnitude to within fractional errors of $\sim {10}^{-3}$, ${10}^{-3}$, ${10}^{-4}$, and ${10}^{-1}$, respectively. LISA should also be able to determine the location of the source in the sky and the SMBH spin orientation to within $\sim {10}^{-4}$ steradians. Furthermore, we show that by including conservative corrections up to 2.5PN order, systematic errors no longer dominate over statistical errors. This shows that search templates that include small body spin effects in the equations of motion up to 2.5PN order should allow us to perform accurate parameter extraction for IMRIs with typical signal-to-noise ratio $\sim 1000$.

We consider a general class of quantum gravity-inspired, modified gravity theories, where the Einstein-Hilbert action is extended through the addition of all terms quadratic in the curvature tensor coupled to scalar fields with standard kinetic energy. This class of theories includes Einstein-Dilaton-Gauss-Bonnet and Chern-Simons modified gravity as special cases. We analytically derive and solve the coupled field equations in the post-Newtonian approximation, assuming a comparable-mass, spinning black hole binary source in a quasicircular, weak-field/slow-motion orbit. We find that a naive subtraction of divergent piece associated with the point-particle approximation is ill-suited to represent compact objects in these theories. Instead, we model them by appropriate effective sources built so that known strong-field solutions are reproduced in the far-field limit. In doing so, we prove that black holes in Einstein-Dilaton-Gauss-Bonnet and Chern-Simons theory can have hair, while neutron stars have no scalar monopole charge, in diametrical opposition to results in scalar-tensor theories. We then employ techniques similar to the direct integration of the relaxed Einstein equations to obtain analytic expressions for the scalar field, metric perturbation, and the associated gravitational wave luminosity measured at infinity. We find that scalar field emission mainly dominates the energy flux budget, sourcing electric-type (even-parity) dipole scalar radiation and magnetic-type (odd-parity) quadrupole scalar radiation, correcting the General Relativistic prediction at relative $-1\mathrm{PN}$ and 2PN orders. Such modifications lead to corrections in the emitted gravitational waves that can be mapped to the parameterized post-Einsteinian framework. Such modifications could be strongly constrained with gravitational wave observations.

We introduce a high-performance implementation of a loosely coherent statistic sensitive to signals spanning a finite-dimensional manifold in parameter space. Results from full-scale simulations on Gaussian noise are discussed, as well as implications for future searches for continuous gravitational waves and related searches for slowly modulated signals, such as emitted by radio pulsars. We demonstrate an improvement of more than an order of magnitude in analysis speed over previously available algorithms. As searches for continuous gravitational waves are computationally limited, the large speedup results in gain in sensitivity.

Even if supersymmetric particles are found at the Large Hadron Collider (LHC), it will be difficult to prove that they constitute the bulk of the dark matter (DM) in the Universe using LHC data alone. We study the complementarity of LHC and DM indirect searches, working out explicitly the reconstruction of the DM properties for a specific benchmark model in the coannihilation region of a 24-parameters supersymmetric model. Combining mock high-luminosity LHC data with presentday null searches for gamma rays from dwarf galaxies with the Fermi Large Area Telescope, we show that current Fermi Large Area Telescope limits already have the capability of ruling out a spurious wino-like solution which would survive using LHC data only, thus leading to the correct identification of the cosmological solution. We also demonstrate that upcoming Planck constraints on the reionization history will have a similar constraining power and discuss the impact of a possible detection of gamma rays from DM annihilation in the Draco dwarf galaxy with a Cherenkov-Telescope-Array-like experiment. Our results indicate that indirect searches can be strongly complementary to the LHC in identifying the DM particles, even when astrophysical uncertainties are taken into account.

Composite Higgs models involving partial compositeness of standard model fermions typically require the introduction of fermionic partners which are relatively light in realistic scenarios. In this paper, we analyze the role of these light custodian fermions in the phenomenology of the composite Higgs models and show that they significantly modify couplings of the Higgs field. We focus on the coupling to gluons, in particular, which is of central importance for Higgs production at the LHC. We show that this coupling can be increased as well as decreased depending on the standard model fermion embedding in the composite multiplets. We also discuss modification of the Higgs couplings to bottom and top quarks and show that modifications to all three couplings—$Hgg$, $H\overline{t}t$, and $H\overline{b}b$—are generically independent parameters.

Lattice simulations on SU(2) and SU(3) gauge theories with matter fields in the fundamental, adjoint, and two index symmetric representations are needed to determine if these theories are near or within the conformal window as required for their applications in beyond standard model phenomenology. Simulations with Wilson fermion action are subject to artifacts linear in the lattice spacing $a$ and must be improved. We provide the necessary coefficients for perturbative improvement of the boundary terms when using Schrödinger functional boundary conditions and furthermore show that correctly implemented $\mathcal{O}(a)$ improved actions are necessary for reliable results.

This paper reports a measurement of $D^{*\pm }$ meson production in jets from proton-proton collisions at a center-of-mass energy of $\sqrt{s}=7\mathrm{TeV}$ at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of $0.30{\mathrm{pb}}^{-1}$ for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range $|\eta |<2.5$. $D^{*\pm }$ mesons found in jets are fully reconstructed in the decay chain: $D^{*+}\to D^0{\pi }^{+}$, $D^0\to K^{-}{\pi }^{+}$, and its charge conjugate. The production rate is found to be $N(D^{*\pm })/N(\mathrm{\text{jet}})=0.025\pm 0.001(\mathrm{stat}.)\pm 0.004(\mathrm{syst}.)$ for $D^{*\pm }$ mesons that carry a fraction $z$ of the jet momentum in the range $0.3<z<1$. Monte Carlo predictions fail to describe the data at small values of $z$, and this is most marked at low jet transverse momentum.

The CLAS detector was used to obtain the first ever measurement of the electromagnetic decay of the ${\Sigma }^{*+}(1385)$ from the reaction $\gamma p\to K^0{\Sigma }^{*+}(1385)$. A real photon beam with a maximum energy of 3.8 GeV was incident on a liquid-hydrogen target, resulting in the photoproduction of the kaon and ${\Sigma }^{*}$ hyperon. Kinematic fitting was used to separate the reaction channel from the background processes. The fitting algorithm exploited a new method to kinematically fit neutrons in the CLAS detector, leading to the measured decay widths ratio ${\Sigma }^{+}(1385)\to {\Sigma }^{+}\gamma /{\Sigma }^{+}(1385)\to {\Sigma }^{+}{\pi }^0=11.95\pm 2.21(\mathrm{stat}{)}_{-1.21}^{+0.53}(\mathrm{sys})\%$ and a deduced partial width of $250.0\pm 56.9(\mathrm{stat}{)}_{-41.2}^{+34.3}(\mathrm{sys})\mathrm{keV}$. A U-spin symmetry test using the SU(3) flavor-multiplet representation yields predictions for the ${\Sigma }^{*+}(1385)\to {\Sigma }^{+}\gamma$ and ${\Sigma }^{*0}(1385)\to \Lambda \gamma$ partial widths that agree with the experimental measurements.

The main topic of this brief report is to discuss the local effects of a cosmological term in the (locally) linearized field equation. It appears the $\Lambda$ imprint is not necessarily spherical, and it is argued that this could have relevant contributions on the local dynamics of clusters and superclusters.

We present an exact solution to the five-dimensional Einstein-Maxwell-dilaton equations describing a static black hole on the Taub-NUT instanton. By construction, the solution does not possess a charge, but is magnetized along the compact dimension. As a limit, we obtain a new regular solution representing a magnetized Kaluza-Klein monopole. We investigate the relevant physical properties and derive the Smarr-like relations.

Warp drives are space-times allowing for superluminal travel. However, they are quantum mechanically unstable because they produce a Hawking-like radiation which is blue shifted at their front wall without any bound. We reexamine this instability when local Lorentz invariance is violated at ultrahigh energy by dispersion, as in some theories of quantum gravity. Interestingly, even though the ultraviolet divergence is now regulated, warp drives are still unstable. Moreover the type of instability is different whether one uses a subluminal or a superluminal dispersion relation. In the first case, a black-hole laser yields an exponential amplification of the emitted flux whereas, in the second, infrared effects produce a linear growth of that flux. These results suggest that chronology could still be protected when violating Lorentz invariance.

We investigate the shadow cast by a rotating braneworld black hole, in the Randall-Sundrum scenario. In addition to the angular momentum, the tidal charge term deforms the shape of the shadow. For a given value of the rotation parameter, the presence of a negative tidal charge enlarges the shadow and reduces its deformation with respect to Kerr spacetime, while for a positive charge, the opposite effect is obtained. We also analyze the case in which the combination of the rotation parameter and the tidal charge results in a naked singularity. We discuss the observational prospects corresponding to the supermassive black hole at the Galactic center.

We show that the scalar wave equation at low frequencies in the Schwarzschild geometry enjoys a hidden $\mathrm{SL}(2,\mathbb{R})$ invariance, which is not inherited from an underlying symmetry of the spacetime itself. Contrary to what happens for Kerr black holes, the vector fields generating the $\mathrm{SL}(2,\mathbb{R})$ are globally defined. Furthermore, it turns out that under an SU(2, 1) Kinnersley transformation, which maps the Schwarzschild solution into the near-horizon limit ${\mathrm{AdS}}_2\times {\mathrm{S}}^2$ of the extremal Reissner-Nordström black hole (with the same entropy), the Schwarzschild hidden symmetry generators become exactly the isometries of the ${\mathrm{AdS}}_2$ factor. Finally, we use the $\mathrm{SL}(2,\mathbb{R})$ symmetry to determine algebraically the quasinormal frequencies of the Schwarzschild black hole and show that this yields the correct leading behavior for large damping.

We investigate noninertial and gravitational effects on quantum states in electromagnetic fields and present the analytic solution for energy eigenstates for the Schrödinger equation including noninertial, gravitational, and electromagnetic effects. We find that in addition to the Landau quantization the rotation of spacetime itself leads to the additional quantization, and that the energy levels for an electron are different from those for a proton at the level of gravitational corrections.