Poletti and Wiltshire have shown that, with the exception of a pure cosmological constant, the solution of a dilaton black hole in the background of de Sitter or anti–de Sitter universe, does not exist in the presence of one Liouville-type dilaton potential. In this work we obtain the dilaton black-hole solutions in the background of the de Sitter or anti–de Sitter universe, with the combination of three Liouville-type dilaton potentials.

For a particle of mass $\mu$ and scalar charge $q$, we compute the effects of the scalar field self-force upon circular orbits, upon slightly eccentric orbits and upon the innermost stable circular orbit (ISCO) of a Schwarzschild black hole of mass $m$. For circular orbits the self-force is outward and causes the angular frequency at a given radius to decrease. For slightly eccentric orbits the self-force decreases the rate of the precession of the orbit. The effect of the self-force moves the radius of the innermost stable circular orbit inward by $0.122701\times q^2/\mu$, and it increases the angular frequency of the ISCO by the fraction $0.0291657\times q^2/\mu m$.

We investigate the possibility that the entropy producing decay of a right-handed sneutrino condensate can simultaneously be the source of the baryon asymmetry, of gravitino dark matter, and of cosmological density perturbations. For generic values of soft supersymmetry breaking terms in the visible sector of 1–10 TeV, condensate decay can yield the dark matter abundance for gravitinos in the mass range 1 MeV to 1 TeV, provided that the resulting reheat temperature is below ${10}^6\mathrm{G}\mathrm{e}\mathrm{V}$. The abundance of thermally produced gravitinos before and after sneutrino decay is then negligible. We consider different leptogenesis mechanisms to generate a sufficient asymmetry, and find that low-scale soft leptogenesis works most naturally at such temperatures. The condensate can easily generate sufficient density perturbations if its initial amplitude is $\sim \mathcal{O}(M_{\mathrm{G}\mathrm{U}\mathrm{T}})$, for a Hubble expansion rate during inflation $>{10}^9\mathrm{G}\mathrm{e}\mathrm{V}$. Right-handed sneutrinos may therefore at the same time provide a source for baryogenesis, dark matter, and the seed of structure formation.

We consider the observational constraints on the running-mass inflationary model, and, in particular, on the scale dependence of the spectral index, from the new cosmic microwave background (CMB) anisotropy measurements performed by WMAP and from new clustering data from the SLOAN survey. We find that the data strongly constraints a significant positive scale dependence of $n$, and we translate the analysis into bounds on the physical parameters of the inflaton potential. Looking deeper into specific types of interaction (gauge and Yukawa) we find that the parameter space is significantly constrained by the new data, but that the running-mass model remains viable.

Because of the tremendous redshift that occurs during the inflationary epoch in the early universe, it has been realized that trans-Planckian physics may manifest itself at energies much lower than the Planck energy. The presence of a fundamental scale suggests that local Lorentz invariance may be violated at sufficiently high energies. Motivated by this possibility, recently, different models that violate Lorentz invariance locally have been used to evaluate the trans-Planckian corrections to the inflationary density perturbation spectrum. However, certain astrophysical observations seem to indicate that local Lorentz invariance may be preserved to extremely high energies. In such a situation, to study the trans-Planckian effects, it becomes imperative to consider models that preserve local Lorentz invariance even as they contain a fundamental scale. In this work, we construct one such model and evaluate the resulting spectrum of density perturbations in the power-law inflationary scenario. While our model reproduces the standard spectrum on small scales, it naturally predicts a suppression of power on large scales. In fact, the spectrum we obtain has some features which are similar to the one that has recently been obtained from noncommutative inflation. However, we find that the amount of suppression predicted by our model is far less than that required to fit the observations. We comment on the fact that, with a suitable choice of initial conditions, our approach can lead to corrections at the infrared as well as at the ultraviolet ends of the spectrum.

We describe a new map-making code for cosmic microwave background observations. It implements fast algorithms for convolution and transpose convolution of two functions on the sphere [B. Wandelt and K. Górski, Phys. Rev. D 63, 123002 (2001)]. Our code can account for arbitrary beam asymmetries and can be applied to any scanning strategy. We demonstrate the method using simulated time-ordered data for three beam models and two scanning patterns, including a coarsened version of the WMAP strategy. We quantitatively compare our results with a standard map-making method and demonstrate that the true sky is recovered with high accuracy using deconvolution map-making.

We show that atmospheric electric fields may affect the cosmic ray observations in several ways and may lead to an overestimation of the cosmic ray energies. The electric field in thunderclouds can be as high as a few kV/cm. This field can accelerate the shower electrons and can feed some additional energy into the shower. Therefore, ground array observations in certain weather conditions may overestimate the energy of ultrahigh-energy cosmic rays if they do not take this effect into account. In addition, the electric field can bend the muon trajectories and affect the direction and energy reconstruction of inclined showers. Finally, there is a possibility of an avalanche multiplication of the shower electrons due to a runaway breakdown, which may lead to a significant miscalculation of the cosmic ray energy.

In a previous work, it was found that the light dark matter scenario could be a possible explanation to the 511 keV emission line detected at the center of our galaxy. Here, we show that hints of this scenario may also have been discovered in particle physics experiments. This could explain the discrepancy between the measurement of the fine structure constant and the value referenced in the CODATA. Finally, our results indicate that some of the light dark matter features could be tested in accelerators. Their discovery might favor $N=2$ supersymmetry.

We trace here instantons through the analysis of pure Yang-Mills gluon Green functions in the Landau gauge for a window of IR momenta ($0.4<k<0.9\mathrm{G}\mathrm{e}\mathrm{V}$). We present lattice results that can be fitted only after substituting the Belavin-Polyakov-Shvarts-Tyupkin profile in the instanton-liquid model (ILM) by one based on the Diakonov and Petrov variational methods. This also leads us to gain information on the parameters of the ILM.

We study $np\to \Lambda {\Theta }^{+}$ and $np\to {\Sigma }^0{\Theta }^{+}$ processes for both of the positive and negative parities of the ${\Theta }^{+}$. Employing the effective chiral Lagrangians for the $KNY$ and $K^{*}NY$ interactions, we calculate differential cross sections as well as total cross sections for the $np\to {\Sigma }^0{\Theta }^{+}$ and $np\to \Lambda {\Theta }^{+}$ reactions. The total cross sections for the positive parity ${\Theta }^{+}$ turn out to be approximately 10 times larger than those for the negative parity ${\Theta }^{+}$ in the range of the c.m. energy $E_{\mathrm{c}.\mathrm{m}.}^{\mathrm{t}\mathrm{h}}\le E_{\mathrm{c}.\mathrm{m}.}\le 3.5\mathrm{G}\mathrm{e}\mathrm{V}$. The results are rather sensitive to the parameters of $K$ exchanges in the $t$ channel.

We show that in hidden local symmetry theory with the vector manifestation (VM), a $K^{+}$ can be bound to skyrmion to give an exotic baryon that has the quantum numbers of the ${\Theta }^{+}$ pentaquark with spin $1/2$ and even parity which is consistent with large $N_c$ counting. The vector meson $K^{*}$ subject to the VM in the chiral limit plays an essential role in inducing the binding.

We estimate final state interactions in the $B$-meson decays into two light vector mesons by the Regge model. We consider Pomeron exchange and charmed Regge trajectories that can relate intermediate charmed particles to the final state. The Regge poles have various helicity-flip residues, which allows a change from the longitudinal to transverse polarization. In this way a significant reduction of the longitudinal polarization fraction can be produced. In the factorization approximation we find agreement with recent data from the BABAR and Belle Collaborations in the $B\to K^{*}\varphi$ decay channel, as a result of an appropriate choice of semileptonic form factors and Regge exchanges. On the other hand, data for the $K^{*}\rho$ decay channels appear more elusive. The soft effects discussed in the present paper are based on a model of Regge trajectories that is shown to reproduce correctly in the noncharmed case the Regge phenomenology of light mesons.

We have studied the inclusive photon spectrum in $\psi (2S)$ decays using the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon transition rates for $\psi (2S)\to \gamma {\chi }_{cJ}(1P)$ ($J=0,1,2$). We also confirm the hindered magnetic dipole (M1) transition, $\psi (2S)\to \gamma {\eta }_c(1S)$. However, the direct M1 transition $\psi (2S)\to \gamma {\eta }_c(2S)$ observed by the Crystal Ball as a narrow peak at a photon energy of 91 MeV is not found in our data.

R-modes of a rotating neutron star are unstable because of the emission of gravitational radiation. We explore the saturation amplitudes of these modes determined by nonlinear mode-mode coupling. Modelling the star as incompressible allows the analytic computation of the coupling coefficients. All couplings up to $n=30$ are obtained, and analytic values for the shear damping and mode normalization are presented. In a subsequent paper we perform numerical simulations of a large set of coupled modes.

We study the finely tuned supersymmetric standard model, recently proposed by Arkani-Hamed and Dimopoulos, at the one loop level. The runnings of the four gaugino Yukawa couplings, the $\mu$ term, the gaugino masses, and the Higgs quartic coupling are computed. The Higgs mass is found to be 130–170 GeV for $M_s>{10}^6\mathrm{G}\mathrm{e}\mathrm{V}$. Measuring the Yukawa coupling constants at the 10% level can begin to constrain the supersymmetry breaking scale. Measuring the relationships between the couplings will provide a striking signal for this model.

We study top quark pair productions at a polarized photon collider from an $e^{+}{e}^{-}$ linear collider (LC) in various improved technicolor models, namely, the one-family walking technicolor model, the top-color-assisted technicolor model, and the top-color-assisted multiscale technicolor model. Recent constraint on the top-pion mass from the precision data of $R_b$ is considered. It is shown that, considering only the statistical errors, a polarized photon collider from a 500 GeV LC with an integrated luminosity of $500{\mathrm{f}\mathrm{b}}^{-1}$ is sufficient for distinguishing the three improved technicolor models experimentally.

Supersymmetric scenarios with inverted mass hierarchy can be hard to observe at a hadron collider, particularly in the nonstrongly interacting sector. We show how the production of stau pairs via gauge boson fusion, along with hard jets in the high rapidity region, can be instrumental in uncovering the signatures of such scenarios. We demonstrate this both in a model-independent way and with reference to some specific, well-motivated models.

We study the behavior of light-cone wave functions, in coarse transverse lattice gauge theory, when one or more parton light-cone momenta are small. This probes the limit of hadron structure at large and small Bjorken $x$. Finite-energy boundary conditions on boundstates allow one to derive the analytic form of wave functions in this region. This leads to simple, universal predictions for the behavior of quark generalized parton distributions near their endpoints. For the first few meson wave functions at large $N_c$, we give the simplest ansatz that incorporates all the boundary conditions.

A simple relation between the total cross section and the forward exponential slope of the elastic differential cross section of $pp$ and $\overline{p}p$ scattering is indicated. An interpretation of this relation is presented as the formation of a black-disk structure for the elastic diffraction interaction of hadron-hadron scattering at the nonasymptotic energy region.

A scenario which overcomes the well-known cosmological overshoot problem associated with stabilizing moduli with steep potentials in string theory is proposed. Our proposal relies on the fact that moduli potentials are very steep and that generically their kinetic energy quickly becomes dominant. However, moduli kinetic energy redshifts faster than other sources when the universe expands. So, if any additional sources are present, even in very small amounts, they will inevitably become dominant. We show that in this case cosmic friction allows the dissipation of the large amount of moduli kinetic energy that is required for the field to be able to find an extremely shallow minimum. We present the idea using analytic methods and verify with some numerical examples.