The inspiral of a stellar mass compact object falling into a massive Kerr black hole can be broken into three different regimes: An adiabatic inspiral phase, where the inspiral time scale is much larger than the orbital period; a late-time radial infall, which can be approximated as a plunging geodesic; and a regime where the body transitions from the inspiral to plunge. In earlier work, Ori and Thorne have outlined a method to compute the trajectory during this transition for a compact object in a circular, equatorial orbit. We generalize this technique to include inclination and eccentricity.

In this paper, second post-Newtonian approximation of Einstein-aether theory is obtained by Chandrasekhar’s approach. Five parametrized post-Newtonian parameters in first post-Newtonian approximation are presented after a time transformation and they are identical with previous works, in which $\gamma =1$, $\beta =1$, and two preferred-frame parameters remain. Meanwhile, in second post-Newtonian approximation, a parameter, which represents third order nonlinearity for gravity, is zero—the same as in general relativity. For an application for future deep space laser ranging missions, we reduce the metric coefficients for light propagation in a case of $N$ point masses as a simplified model of the Solar System. The resulting light deflection angle in second post-Newtonian approximation poses another constraint on the Einstein-aether theory.

We study the thermodynamics associated to topological black hole solutions of AdS gravity coupled to nonlinear electrodynamics (Born-Infeld) in any dimension, using a background-independent regularization prescription for the Euclidean action given by boundary terms, which explicitly depend on the extrinsic curvature (Kounterterms series). A finite action principle leads to the correct definition of thermodynamic variables as Noether charges, which satisfy a Smarr-like relation. In particular, for the odd-dimensional case, a consistent thermodynamic description is achieved if the internal energy of the system includes the vacuum energy for AdS spacetime.

Recent calculations of the recoil velocity in black-hole binary mergers have found kick velocities of $\approx 2500\mathrm{km}/\mathrm{s}$ for equal-mass binaries with antialigned initial spins in the orbital plane. In general the dynamics of spinning black holes can be extremely complicated and are difficult to analyze and understand. In contrast, the “superkick” configuration is an example with a high degree of symmetry that also exhibits exciting physics. We exploit the simplicity of this test case to study more closely the role of spin in black-hole recoil and find that the recoil is with good accuracy proportional to the difference between the $(l=2,m=\pm 2)$ modes of ${\Psi }_4$, the major contribution to the recoil occurs within $30M$ before and after the merger, and that this is after the time at which a standard post-Newtonian treatment breaks down. We also discuss consequences of the $(l=2,m=\pm 2)$ asymmetry in the gravitational wave signal for the angular dependence of the signal-to-noise ratio and the mismatch of the gravitational wave signals corresponding to the north and south poles.

The methods of effective field theory are used to study generic theories of inflation with a single inflaton field. For scalar modes, the leading corrections to the $\mathcal{R}$ correlation function are found to be purely of the $k$-inflation type. For tensor modes the leading corrections to the correlation function arise from terms in the action that are quadratic in the curvature, including a parity-violating term that makes the propagation of these modes depend on their helicity. These methods are also briefly applied to nongeneric theories of inflation with an extra shift symmetry, as in so-called ghost inflation.

We present an analysis of anisotropic baryon acoustic oscillations and elucidate how a mis-estimation of the cosmology, which leads to incorrect values of the angular diameter distance, $d_A$, and Hubble parameter, $H$, manifest themselves in changes to the monopole and quadrupole power spectrum of biased tracers of the density field. Previous work has focused on the monopole power spectrum, and shown that the isotropic dilation combination $d_A^2{H}^{-1}$ is robustly constrained by an overall shift in the scale of the baryon feature. We extend this by demonstrating that the quadrupole power spectrum is sensitive to an anisotropic warping mode $d_{A}H$, allowing one to break the degeneracy between $d_A$ and $H$. We describe a method for measuring this warping, explicitly marginalizing over the form of redshift-space distortions. We verify this method on $N$-body simulations and estimate that $d_{A}H$ can be measured with a fractional accuracy of $\sim (3/\sqrt{V})\%$ where the survey volume is estimated in $h^{-3}{\mathrm{Gpc}}^3$.

We develop a new interpolation scheme, based on harmonic inpainting, for reconstructing the cosmic microwave backgroundtemperature data within the Galaxy mask from the data outside the mask. We find that, for scale-invariant isotropic random Gaussian fluctuations, the developed algorithm reduces the errors in the reconstructed map for the odd-parity modes significantly for azimuthally symmetric masks with constant galactic latitudes. For a more realistic Galaxy mask, we find a modest improvement in the even-parity modes as well.

We consider linear perturbation equations for long-wavelength scalar metric perturbations in generalized gravity, applicable to nonsingular cosmological models including a bounce from collapse to expansion in the very early universe. We present the general form for the perturbation equations, which follows from requiring that the inhomogeneous universe on large scales obeys the same local equations as the homogeneous Friedmann-Robertson-Walker background cosmology (the separate universes approach). In a pseudolongitudinal gauge this becomes a homogeneous second-order differential equation for adiabatic perturbations, which reduces to the usual equation for the longitudinal gauge metric perturbation in general relativity with vanishing anisotropic stress. As an application we show that the scale-invariant spectrum of perturbations in the longitudinal gauge generated during an ekpyrotic collapse are not transferred to the growing mode of adiabatic density perturbations in the expanding phase in a simple bounce model.

Our space-time is filled with gravitational wave backgrounds that constitute a fluctuating environment created by astrophysical and cosmological sources. Bounds on these backgrounds are obtained from cosmological and astrophysical data but also by analysis of ranging and Doppler signals from distant spacecraft. We propose here a new way to set bounds on those backgrounds by performing clock comparisons between a ground clock and a remote spacecraft equipped with an ultrastable clock, rather than only ranging to an on-board transponder. This technique can then be optimized as a function of the signal to be measured and the dominant noise sources, leading to significant improvements on present bounds in a promising frequency range where different theoretical models are competing. We illustrate our approach using the SAGAS project which aims to fly an ultrastable optical clock in the outer solar system.

The concepts of pole mass and width are extended to unstable fermions in the general framework of parity-nonconserving gauge theories, such as the standard model. In contrast with the conventional on-shell definitions, these concepts are gauge independent and avoid severe unphysical singularities, properties of great importance since most fundamental fermions in nature are unstable particles. General expressions for the unrenormalized and renormalized dressed propagators of unstable fermions and their field-renormalization constants are presented.

Although mirage mediation is one of the most plausible mediation mechanisms of supersymmetry breaking, it suffers from two crucial problems. One is the $\mu /B\mu$ problem, and the second is the cosmological one. The former stems from the fact that the $B$ parameter tends to be comparable with the gravitino mass, which is 2 orders of magnitude larger than the other soft masses. The latter problem is caused by the decay of the modulus whose branching ratio into the gravitino pair is sizable. In this paper, we propose a model of mirage mediation, in which Peccei-Quinn symmetry is incorporated. In this axionic mirage mediation, it is shown that the Peccei-Quinn symmetry breaking scale is dynamically determined around ${10}^{10}\mathrm{GeV}$ to ${10}^{12}\mathrm{GeV}$ due to the supersymmetry breaking effects, and the $\mu$ problem can be solved naturally. Furthermore, in our model, the lightest supersymmetric particle (LSP) is the axino, that is, the superpartner of the axion. The overabundance of the LSPs due to decays of the modulus/gravitino, which is the most serious cosmological difficulty in the mirage mediation, can be avoided if the axino is sufficiently light. The next-LSPs (NLSPs) produced by the gravitino decay eventually decay into the axino LSPs, yielding the dominant component of the axinos remaining today. It is shown that the axino with a mass of $\mathcal{O}(100)\mathrm{MeV}$ is naturally realized, which can constitute the dark matter of the Universe, with a free-streaming length of the order of $0.1\mathrm{Mpc}$. The saxion, the real scalar component of the axion supermultiplet, can also be cosmologically harmless due to the dilution of the modulus decay. The lifetime of the NLSP is relatively long, but much shorter than 1 sec, when the big-bang nucleosynthesis commences. The decay of the NLSP would provide intriguing collider signatures.

We study how the properties of the four neutralino states, ${\chi }_i$ ($i=1$, 2, 3, 4), can be investigated at the Large Hadron Collider (LHC), in the case when the lightest one, ${\chi }_1$, has a mass $m_{\chi }\lesssim 50\mathrm{GeV}$ and is stable. This situation arises naturally in supersymmetric models where gaugino masses are not unified at a grand unified (GUT) scale and R-parity is conserved. The main features of these neutralino states are established by analytical and numerical analyses, and two scenarios are singled out on the basis of the cosmological properties required for the relic neutralinos. Signals expected at LHC are discussed through the main chain processes started by a squark, produced in the initial proton-proton scattering. We motivate the selection of some suitable benchmarks, in light of the spectroscopical properties (mass spectrum and transitions) of the four neutralino states. Branching ratios and the expected total number of events are derived in the various benchmarks, and their relevance for experimental determination of neutralino properties is finally discussed.

We investigate a neutrino mass model in which the neutrino data is accounted for by bilinear R-parity violating supersymmetry with anomaly mediated supersymmetry breaking. We focus on the CERN Large Hadron Collider (LHC) phenomenology, studying the reach of generic supersymmetry search channels with leptons, missing energy and jets. A special feature of this model is the existence of long-lived neutralinos and charginos which decay inside the detector leading to detached vertices. We demonstrate that the largest reach is obtained in the displaced vertices channel and that practically all of the reasonable parameter space will be covered with an integrated luminosity of $10{\mathrm{fb}}^{-1}$. We also compare the displaced vertex reaches of the LHC and Tevatron.

We propose an extension of the hard-wall AdS/QCD model by including the Chern-Simons term required to reproduce the chiral anomaly of QCD. In the framework of this holographic model, we study the vertex function $F_{\pi {\gamma }^{*}{\gamma }^{*}}(Q_1^2,Q_2^2)$ which accumulates information about the coupling of the pion to two (in general virtual) photons. We calculate the slope of the form factor with one real and one slightly virtual photon and show that it is close to experimental findings. We analyze the formal limit of large virtualities and establish that predictions of the holographic model analytically (including nontrivial dependence on the ratio of photon virtualities) coincide with those of perturbative QCD calculated for the asymptotic form of the pion distribution amplitude. We also investigate the generalized vector-meson-dominance structure of $F_{\pi {\gamma }^{*}{\gamma }^{*}}(Q_1^2,Q_2^2)$ in the extended AdS/QCD model.

We present extensive studies on hot and dense quark matter with two light and one heavy flavors in the Nambu–Jona-Lasinio model with the Polyakov loop (so-called PNJL model). First we discuss prescription dependence in choosing the Polyakov loop effective potential and propose a simple and rather sensible ansatz. We look over quantitative comparison to the lattice measurement to confirm that the model captures thermodynamic properties correctly. We then analyze the phase structure by changing the temperature, quark chemical potential, quark masses, and coupling constants. We particularly investigate how the effective ${\mathrm{U}}_{\mathrm{A}}(1)$ restoration and the induced vector-channel interaction at finite density would affect the QCD critical point.

We calculate in perturbative QCD the transverse momentum broadening of vector boson production in high energy nuclear collisions. We evaluate the effect of initial-state parton multiple scattering for the production of the Drell-Yan virtual photon and $W/Z$ bosons. We calculate both the initial- and final-state multiple scattering effect for the production of heavy quarkonia and their transverse momentum broadening in both nonrelativistic QCD and the color evaporation model of quarkonium formation. We find that $\mathrm{J}/\psi$ and ${\rm Y}$ broadening in hadron-nucleus collision is close to $2C_A/C_F$ times the corresponding Drell-Yan broadening, which gives a good description of existing Fermilab data. Our calculations are also consistent with Relativistic Heavy Ion Collider data on $\mathrm{J}/\psi$ broadening in relativistic heavy ion collisions. We predict the transverse momentum broadening of vector boson ($\mathrm{J}/\psi$, ${\rm Y}$, and $W/Z$) production in relativistic heavy ion collisions at the Large Hadron Collider and discuss the role of the vector boson broadening in diagnosing medium properties.

We have computed the complete one-loop electroweak effects in the minimal supersymmetric standard model for single top (and single antitop) production in the $t$ channel at hadron colliders, generalizing a previous analysis performed for the dominant $dt$ final state and fully including QED effects. The results are quite similar for all processes. The overall standard model one-loop effect is small, of the few percent size. This is due to a compensation of weak and QED contributions that are of opposite sign. The genuine supersymmetry contribution is generally quite modest in the minimal supergravity scenario. The experimental observables would therefore only practically depend, in this framework, on the Cabibbo-Kobayashi-Maskawa $Wtb$ coupling.

In this paper, we consider the role that worldsheet instantons in the heterotic string could play in spin-statistics violations. Such violations are nonperturbative in the string tension and so would not appear in the spacetime effective action, producing a unique signature of string theory and the details of compactification. By performing a Bogomol’nyi transformation it is shown that there are no instanton solutions in the simplest model proposed by Harvey and Liu, but it is conjectured that more sophisticated models may yield solutions. If such instantons do exist, their effect might be measured by upcoming experiments.

The effects of a nonvanishing value for the cosmological constant in the scenario of Lorentz symmetry breaking recently proposed by Cohen and Glashow (which they denote as very special relativity) are explored and observable consequences are pointed out.