We study the phase-space structure of a dark-matter halo formed in a high resolution simulation of a ΛCDM cosmology. Our goal is to quantify how much substructure is left over from the inhomogeneous growth of the halo, and how it may affect the signal in experiments aimed at detecting the dark matter particles directly. If we focus on the equivalent of “solar vicinity,” we find that the dark matter is smoothly distributed in space. The probability of detecting particles bound within dense lumps of individual mass less than ${10}^7{M}_{\odot }{h}^{-1}$ is small, less than ${10}^{-2}.$ The velocity ellipsoid in the solar neighborhood deviates only slightly from a multivariate Gaussian, and can be thought of as a superposition of thousands of kinematically cold streams. The motions of the most energetic particles are, however, strongly clumped and highly anisotropic. We conclude that experiments may safely assume a smooth multivariate Gaussian distribution to represent the kinematics of dark-matter particles in the solar neighborhood. Experiments sensitive to the direction of motion of the incident particles could exploit the expected anisotropy to learn about the recent merging history of our Galaxy.

We study the cosmic density perturbations induced from the fluctuation of the amplitude of late-decaying scalar condensations (called $\phi )$ in the scenario where the scalar field $\phi$ once dominates the universe. In such a scenario, the cosmic microwave background (CMB) radiation originates to decay products of the scalar condensation and hence its anisotropy is affected by the fluctuation of $\phi .$ It is shown that the present cosmic density perturbations can be dominantly induced from the primordial fluctuation of $\phi ,$ not from the fluctuation of the inflaton field. This scenario may change constraints on the source of the density perturbations, like inflation. In addition, a correlated mixture of adiabatic and isocurvature perturbations may arise in such a scenario; possible signals in the CMB power spectrum are discussed. We also show that the simplest scenario of generating the cosmic density perturbations only from the primordial fluctuation of $\phi$ (i.e., the so-called “curvaton” scenario) is severely constrained by the current measurements of the CMB angular power spectrum if the correlated mixture of the adiabatic and isocurvature perturbations are generated.

Mirror symmetry is a plausible candidate for a fundamental symmetry of particle interactions which can be exactly conserved if a set of mirror particles exist. The properties of the mirror particles seem to provide an excellent candidate to explain the inferred dark matter of the Universe and might also be responsible for a variety of other puzzles in particle physics, astrophysics, meteoritics and planetary science. One such puzzle—the orthopositronium lifetime problem—can be explained if there is a small kinetic mixing of ordinary and mirror photons. We show that this kinetic mixing implies the existence of ordinary atom–mirror-atom bound states with interesting terrestrial and astrophysical implications. We suggest that sensitive mass spectroscopic studies of ordinary samples containing heavy elements such as lead might reveal the presence of these bound states, as they would appear as anomalously heavy elements. In addition to the effects of single mirror atoms, collective effects from embedded fragments of mirror matter (such as mirror iron microparticles) are also possible. We speculate that such mirror matter fragments might explain a mysterious UV photon burst observed coming from a laser irradiated lead target in a recent experiment.

We calculate expressions for the quadrupole moments of nonstrange baryons in which the number of QCD color charges is $N_c.$ Using only the assumption of single-photon exchange, we obtain 4 relations among the 6 moments, and show how all of them may be obtained from $Q_{{\Delta }^{+}p}$ up to ${O(1/N}_c^2)$ corrections. We compare to the $N_c=3\mathrm{}$ case, and obtain relations between the neutron charge radius and quadrupole moments. We also discuss prospects for the measurement of these moments.

Quenched QCD has a $Z_3$ phase transition which is explicitly broken for dynamical calculations. Knowing whether or not the chiral phase transition occurs at the same temperature for all $Z_3$ sectors and whether this critical temperature coincides with the deconfinement transition could be crucial to understand the underlying microscopic dynamics also for the full theory. We use the existence of a gap in the Dirac spectrum as an order parameter for the restoration of chiral symmetry. We find that the spectral gap opens up at the same critical temperature in all $Z_3$ sectors in contrast with earlier claims in the literature.

Motivated by the recent strong experimental evidence of large ${\nu }_{\mu }-{\nu }_{\tau }$ neutrino mixing, we explore current bounds on the analogous mixing in the charged lepton sector. We present a general formalism for dimension-6 fermionic effective operators involving $\tau -\mu$ mixing with a typical Lorentz structure $\left(\overline{\mu }\Gamma \tau \right)\left(q^{\alpha }\Gamma q^{\beta }\right),$ and discuss their relationship to the standard model gauge symmetry and the underlying flavor dynamics. We derive the low-energy constraints on the new physics scale associated with each operator, mostly from current experimental bounds on rare decay processes of $\tau ,$ hadrons or heavy quarks. For operators involving at least one light quark $\mathrm{}(u,d,s),$ these constraints typically give a bound on the new physics scale of a few TeV or higher. Those operators with two heavy quarks turn out to be more weakly constrained at the present, giving bounds of a few hundred GeV. A few scalar and pseudoscalar operators are free from all current experimental constraints.

The maximally supersymmetric type IIB $\mathrm{pp}$ wave is compactified on spatial circles, with and without an auxiliary rotational twist. All spatial circles of constant radius are identified. Without the twist, an $S^1$ compactification can preserve 24, 20 or 16 supercharges. $T^2$ compactifications can preserve 20, 18 or 16 supercharges; $T^3$ compactifications can preserve 18 or 16 supercharges and higher compactifications preserve 16 supercharges. The world sheet theory of this background is discussed. The T dual and decompactified type IIA and M-theoretic solutions which preserve 24 supercharges are given. Some comments are made regarding the AdS parent and the CFT description.

We present a new approximate method for constructing gravitational radiation driven inspirals of test bodies orbiting Kerr black holes. Such orbits can be fully described by a semilatus rectum p, an eccentricity e, and an inclination angle $\iota ,$ or, by an energy E, an angular momentum component $L_z,$ and a third constant Q. Our scheme uses expressions that are exact (within an adiabatic approximation) for the rates of change $(\mathrm{ṗ},ė,\dot{\iota })$ as linear combinations of the fluxes $(Ė,L_z,\mathrm{Q̇}),$ but uses quadrupole-order formulas for these fluxes. This scheme thus encodes the exact orbital dynamics, augmenting it with an approximate radiation reaction. Comparing inspiral trajectories, we find that this approximation agrees well with numerical results for the special cases of eccentric equatorial and circular inclined orbits, far more accurate than corresponding weak-field formulas for $(\mathrm{ṗ},ė,\dot{\iota }).\mathrm{}$ We use this technique to study the inspiral of a test body in inclined, eccentric Kerr orbits. Our results should be useful tools for constructing approximate waveforms that can be used to study data analysis problems for the future Laser Interferometer Space Antenna gravitational-wave observatory, in lieu of waveforms from more rigorous techniques that are currently under development.

In this paper I consider the collision of black holes with parallel spins using first order perturbation theory of rotating black holes (the Teukolsky formalism). The black holes are assumed to be close to each other, initially nonboosted and spinning slowly. I estimate the properties of the gravitational radiation released from such a collision. The same problem was studied recently by Gleiser and Dominguez [Phys. Rev. D 65, 064018 (2002)] in the context of the Zerilli perturbation formalism and my results for waveforms, energy, and angular momentum radiated agree very well with the results presented in that work.

Using a novel approach, we work out the general relativistic effects on the quantum interference of de Broglie waves associated with thermal neutrons. The unified general formula is consistent with special relativistic results in the flat space limit. It is also shown that the exact geodesic equation contains in a natural way a gravitational analogue of the Aharonov-Bohm effect. We work out two examples, one in general relativity and the other in heterotic string theory, in order to obtain the first order gravitational correction terms to the quantum fringe shift. Measurement of these terms is closely related to the validity of the equivalence principle at a quantum level.

Applying our recently developed propagation code we review extragalactic neutrino fluxes above ${10}^{14}\mathrm{eV}$ in various scenarios and how they are constrained by current data. We specifically identify scenarios in which the cosmogenic neutrino flux above $\simeq {10}^{18}\mathrm{eV},$ produced by pion production of ultrahigh energy cosmic rays outside their sources, is considerably higher than the “Waxman-Bahcall bound.” This is easy to achieve for sources with hard injection spectra and luminosities that were higher in the past. Such fluxes would significantly increase the chances to detect ultrahigh energy neutrinos with experiments currently under construction or in the proposal stage.

We calculate neutrino emissivities from the decay and scattering of Goldstone bosons in the color-flavor-locked (CFL) phase of quarks at high baryon density. Interactions in the CFL phase are described by an effective low-energy theory. For temperatures in the tens of keV range, relevant to the long-term cooling of neutron stars, the emissivities involving Goldstone bosons dominate over those involving quarks, because gaps in the CFL phase are $\sim 100\mathrm{MeV}$ while the masses of Goldstone modes are on the order of 10 MeV. For the same reason, the specific heat of the CFL phase is also dominated by the Goldstone modes. Notwithstanding this, both the emissivity and the specific heat from the massive modes remain rather small, because of their extremely small number densities. The values of the emissivity and the specific heat imply that the time scale for the cooling of the CFL core is $\sim {10}^{26}\mathrm{y}\mathrm{r},$ which makes the CFL phase invisible as the exterior layers of normal matter surrounding the core will continue to cool through significantly more rapid processes. If the CFL phase appears during the evolution of a protoneutron star, neutrino interactions with Goldstone bosons are expected to be significantly more important since temperatures are high enough $(\sim 20–40\mathrm{MeV})$ to admit large number densities of Goldstone modes.

We analyze the most recent experimental data regarding $D^0-\overline{D^0}$ mixing, allowing for $\mathrm{CP}$ violation. We focus on the dispersive part of the mixing amplitude, $M_{12}^D,$ which is sensitive to new physics contributions. We obtain a constraint on the mixing amplitude: $|M_{12}^D|<~6.2\times {10}^{-11}\mathrm{MeV}$ at 95% C.L. This constraint is weaker by a factor of about three than the one which is obtained when no $\mathrm{CP}$ violation is assumed.

The existence of large ${\nu }_{\mu }-{\nu }_{\tau }$ mixing suggests the likelihood of large smuon-stau mixing in supersymmetric models, leading to μ and τ number violation. In addition to interesting signatures in slepton and neutralino production and decay, this will lead to rare τ decays, such as $\overrightarrow{\tau }\mu \gamma .$ Recently, it has been pointed out that the $\overrightarrow{\tau }3\mu$ branching ratio could be substantial in the large $\tan \beta$ region of parameter space, due to an induced $\mu -\tau$-Higgs vertex. In this paper, another signature, $\overrightarrow{\tau }\mu \eta$ is considered. In the large $\tan \beta$ region, it is shown that the branching ratio of $\overrightarrow{\tau }\mu \eta$ is 8.4 times the branching ratio of $\overrightarrow{\tau }3\mu ,$ independent of any unknown parameters, and it will thus give the most stringent bound on Higgs-mediated lepton flavor violation, and may provide its first signature. In the other regions of parameter space, where $\overrightarrow{\tau }\mu \gamma$ is the most prominent decay, the branching ratio for $\overrightarrow{\tau }\mu \eta$ is always substantially lower.

We analyze the flavor changing neutral current semileptonic decay $\overrightarrow{B}{X}_s{l}^{+}{l}^{-}$ in a fully left-right supersymmetric model. We give explicit expressions for all the amplitudes involved in the process, and compare the numerical results with experimental bounds, in both the constrained case (where the only flavor violation comes from the Cabibbo-Kobayashi-Maskawa matrix) and the unconstrained case (including soft breaking supersymmetry terms). Stringent constraints on the parameter space of the model are obtained. We also include constraints from $\overrightarrow{b}s\gamma .$

We use the simple instanton motivated Nambu–Jona-Lasinio–type model to calculate a twist 3 pseudoscalar pion light cone wave function ${\psi }_{\pi }^{\mathrm{PS}}.$ Using the normalization condition for ${\psi }_{\pi }^{\mathrm{PS}}$ we calculate the quark condensate and also the gluon condensate, which agree with the phenomenological values for these quantities. Since we can compute also the $k_T^2$ dependence of the light cone wave functions, we calculate $k_T^2$ moments of the pseudoscalar and axial-vector wave functions which are related to the mixed vacuum condensates. This allows us to extract the condensates and compare them with existing estimates.

We apply methods of dynamical systems to study the behavior of the Randall-Sundrum models. We determine evolutionary paths for all possible initial conditions in a two-dimensional phase space and we investigate the set of accelerated models. The simplicity of our formulation in comparison to some earlier studies is expressed in the following: our dynamical system is a two-dimensional Hamiltonian system, and what is more advantageous, it is free from the degeneracy of critical points so that the system is structurally stable. The phase plane analysis of Randall-Sundrum models with isotropic Friedmann geometry clearly shows that qualitatively we deal with the same types of evolution as in general relativity, although quantitatively there are important differences.

The structure of 3-jet $e^{+}{e}^{-}\to b\overline{b}g$ events has been studied using hadronic $Z^0$ decays recorded in the SLC Large Detector experiment at SLAC. Three-jet final states were selected and the charge-coupled-device-based vertex detector was used to identify two of the jets as b or $\overline{b};$ the remaining jet in each event was tagged as the gluon jet. Distributions of the gluon energy and polar angle with respect to the electron beam were measured over the full kinematic range, and used to test the predictions of perturbative QCD. We find that beyond-leading-order QCD calculations are needed to reproduce the features seen in the data. The energy distribution is sensitive to an anomalous b chromomagnetic moment κ at the $b\overline{b}g$ vertex. We measured κ to be consistent with zero and set 95% confidence level limits on its value, $-0.06<\mathrm{}\kappa <\mathrm{0.04.}\mathrm{}$