Flat directions in the minimal supersymmetric standard model are known to deform into nontopological solitons, Q balls, which generally possess both baryon and lepton asymmetries. We investigate how Q balls evolve if some of the constituent fields of the flat direction decay into light species. It is found that the Q balls takes a new configuration whose energy per charge slightly increases due to the decay. Specifically, we show that all the stable Q balls eventually transform into pure B balls via the decay into neutrinos.

In this paper we describe the evolution of various expanding and contracting phases before the “bounce” in Einstein frame. Focusing on the case of a single scalar field, in terms of the parameter w of the state equation, four different regions denoting different expanding and contracting phases are pointed out. We discuss possible scenarios generating the nearly scale-invariant spectrum and show that the inflation and other alternative scenarios recently proposed can be placed in different positions of these regions. Our work offers an interesting classification for the primordial perturbation spectra from various phases before the “bounce,” which may have important implications for building an early universe scenario embedded in possible high-energy theories.

We propose a novel representation of cosmic microwave anisotropy maps, where each multipole order $\mathcal{l}$ is represented by $\mathcal{l}$ unit vectors pointing in directions on the sky and an overall magnitude. These “multipole vectors and scalars” transform as vectors under rotations. Like the usual spherical harmonics, multipole vectors form an irreducible representation of the proper rotation group $\mathrm{SO}\left(3\right).$ However, they are related to the familiar spherical harmonic coefficients $a_{\mathcal{l}m}$ in a nonlinear way and are therefore sensitive to different aspects of the cosmic microwave background (CMB) anisotropy. Nevertheless, it is straightforward to determine the multipole vectors for a given CMB map and we present an algorithm to compute them. A code implementing this algorithm is available at http://www.phys.cwru.edu/projects/mpvectors/. Using the Wilkinson Microwave Anisotropy Probe (WMAP) full-sky maps, we perform several tests of the hypothesis that the CMB anisotropy is statistically isotropic and Gaussian random. We find that the result from comparing the oriented area of planes defined by these vectors between multipole pairs $2<~{\mathcal{l}}_1\ne {\mathcal{l}}_2<~8$ is inconsistent with the isotropic Gaussian hypothesis at the 99.4% level for the internal linear combination map and at 98.9% level for the cleaned map of Tegmark et al. A particular correlation is suggested between the $\mathcal{l}=3\mathrm{}$ and $\mathcal{l}=8\mathrm{}$ multipoles, as well as several other pairs. This effect is entirely different from the now familiar planarity and alignment of the quadrupole and octupole: while the aforementioned is fairly unlikely, the multipole vectors indicate correlations not expected in Gaussian random skies that make them unusually likely. The result persists after accounting for pixel noise and after assuming a residual 10% dust contamination in the cleaned WMAP map. While the definitive analysis of these results will require more work, we hope that multipole vectors will become a valuable tool for various cosmological tests, in particular those of cosmic isotropy.

Observation of thousands of type Ia supernovae should offer the most direct approach to probe the dark energy content of the Universe. This will be undertaken by future large ground-based surveys followed by a space mission (SNAP/JDEM). We address the problem of extracting the cosmological parameters from future data in a model independent approach, with minimal assumptions on the prior knowledge of some parameters. We concentrate on the comparison between a fiducial model and the fitting function and address in particular the effect of neglecting (or not) the time evolution of the equation of state. We present a quantitative analysis of the bias that can be introduced by the fitting procedure. Such a bias cannot be ignored as soon as the statistical errors from present data are drastically improved.

We discuss the connection between dark radiation on the brane and the bulk gravitational field in a dilatonic brane world model proposed by Koyama and Takahashi where the exact solutions for the five-dimensional cosmological perturbations can be obtained analytically. It is shown that the dark radiation perturbation is related to the non-normalizable Kaluza-Klein (KK) mode of the bulk perturbations. For the de Sitter brane in the anti–de Sitter bulk, the squared mass of this KK mode is ${2H}^2,$ where H is the Hubble parameter on the brane. This mode is shown to be connected to the excitation of a small black hole in the bulk in the long wavelength limit. The exact solution for anisotropic stress on the brane induced by this KK mode is found, which plays an important role in the calculation of cosmic microwave background radiation anisotropies in the brane world.

We have examined the effects of a bound dineutron ${}^{2}n$ upon big bang nucleosynthesis (BBN) as a function of its binding energy $B_{{}^2\mathrm{n}}.$ We find a weakly bound dineutron has little impact but as $B_{{}^2\mathrm{n}}$ increases its presence begins to alter the flow of free nucleons to helium-4. Because of this disruption, and in the absence of changes to other binding energies or fundamental constants, BBN sets a reliable upper limit of $B_{{}^2\mathrm{n}}\lesssim 2.5\mathrm{MeV}$ in order to maintain the agreement with the observations of the primordial helium-4 mass fraction and D/H abundance. We also consider simultaneous variations in $B_{{}^2\mathrm{n}}$ and the deuteron binding energy $B_{\mathrm{D}}$ using a simplified BBN calculation. We demonstrate that only when $B_{\mathrm{D}}$ is very close to 1.7 MeV does the $B_{{}^2\mathrm{n}}$ upper limit increase to 3.5 MeV, a value set by incompatibility of an observed primordial $A=2\mathrm{}$ abundance with the decay of deuterons.

We discuss the Einstein energy-momentum complex and the Bergmann-Thomson angular momentum complex in general relativity and calculate them for space-time homogeneous Gödel universes. The calculations are performed for a dust acausal Gödel model and for a scalar-field causal Gödel model. It is shown that the Einstein pseudotensor is traceless, not symmetric, the gravitational energy “density” is negative, and that the gravitational Poynting vector vanishes. Significantly, the total (gravitational and matter) energy “density” for the acausal model is zero while for the causal model it is negative. The Bergmann-Thomson angular momentum complex does not vanish for both Gödel models.

In this article we show that the mainly spacetime w modes may become unstable in a rotating ultracompact $\mathrm{}(R<\mathrm{}3M)\mathrm{}$ relativistic star. We provide results for the axial modes of a rotating star in the slow rotation approximation, and demonstrate that an instability may become active in stars with an ergosphere. This suggests a close association with the so-called “ergosphere instability” discussed by other authors. The unstable modes are found to grow on a time scale of seconds to minutes. We discuss briefly whether the instability is likely to have any astrophysical relevance.

Binary systems of massive black holes will be detectable by the Laser Interferometer Space Antenna (LISA) throughout the entire Universe. Observations of gravitational waves from this class of sources will have important repercussions on our understanding of the behavior of gravity in the highly nonlinear relativistic regime, the distribution and interaction of massive black holes at high redshift, and the formation and evolution of cosmic structures. It is therefore important to address how accurately LISA can measure the source parameters and explore the implications for astronomy and cosmology. Present observations and theoretical models suggest that massive black holes could be spinning, possibly rapidly in some cases. In binary systems, the relativistic spin-orbit interaction causes the orbital plane to precess in space, producing a characteristic signature on the emitted gravitational waves. In this paper we investigate the effect of spins on the gravitational wave signal registered at the LISA output—we provide ready-to-use analytical expressions of the measured signal—and the implications for parameter estimation. We consider the inspiral phase of binary systems in circular orbit undergoing the so-called “simple precession” and we approximate the gravitational radiation at the restricted ${\mathrm{post}}^{1.5}$-Newtonian order. We show that the presence of spins changes dramatically the signature of the signal recorded by LISA. As a consequence, the mean square errors associated with the parameter measurements are significantly smaller than the ones obtained when the effect of spins is neglected. For a binary system of two ${10}^6{M}_{\odot }$ black holes, the angular resolution and the relative error on the luminosity distance improve by a factor of $\approx 3–10;$ the fractional errors on the chirp mass and the reduced mass decrease by a factor of $\sim 10$ and $\sim {10}^3,$ respectively.

It is shown that any spatially flat and isotropic universe undergoing accelerated expansion driven by a self-interacting scalar field can be directly related to a contracting, decelerating cosmology. The duality is made manifest by expressing the scale factor and Hubble parameter as functions of the scalar field and simultaneously interchanging these two quantities. The decelerating universe can be twinned with a cosmology sourced by a phantom scalar field by inverting the scale factor and leaving the Hubble parameter invariant. The accelerating model can be related to the same phantom universe by identifying the scale factor with the inverse of the Hubble parameter. The duality between accelerating and decelerating backgrounds can be extended to spatially curved cosmologies and models containing perfect fluids. A similar triality and associated scale factor duality is found in the Randall-Sundrum type II braneworld scenario.

We analyze the effects of the current neutrino data on thermal leptogenesis and $0\nu \beta \beta$ decay in a fully left-right extension of the minimal supersymmetric model. The model has several additional phases compared to the minimal supersymmetric model. These phases appear from both the heavy and light neutrino sectors: two CKM-type phases and four Majorana phases which give new contributions to CP-violating parameters and leptogenesis. We study observable effects of these phases on leptogenesis in most general neutrino mixing scenarios, with either hierarchical, inverse hierarchical, or quasidegenerate light and heavy neutrinos. We comment on the effects of these scenarios on the $0\nu \beta \beta$ decay. The CP-violating phases in both the heavy and light neutrino sectors of the left-right supersymmetric model have unique features, resulting in bounds on heavy neutrino masses different from the minimal scenario in leptogenesis, and which may distinguish the model from other supersymmetric scenarios.

We calculate exactly functional determinants for quantum oscillations about periodic instantons with a nontrivial value of the Polyakov line at spatial infinity. Hence, we find the weight or the probability with which calorons with nontrivial holonomy occur in the Yang-Mills partition function. The weight depends on the value of the holonomy, the temperature, ${\Lambda }_{\mathrm{QCD}},$ and the separation between the BPS monopoles (or dyons) that constitute the periodic instanton. At large separation between constituent dyons, the quantum measure factorizes into a product of individual dyon measures, times a definite interaction energy. We present an argument that at temperatures below a critical one related to ${\Lambda }_{\mathrm{QCD}},$ trivial holonomy is unstable, and that calorons “ionize” into separate dyons.

A class of predictive SO(10) grand unified theories with highly asymmetric mass matrices, known as lopsided textures, which was developed to accommodate the observed mixing in the neutrino sector, can effectively determine the rate for charged lepton flavor violation (LFV), and in particular the branching ratio for $\overrightarrow{\mu }e\gamma .$ Assuming that the supersymmetric GUT breaks directly to the constrained minimal supersymmetric standard model (CMSSM), we find that in light of the combined constraints on the CMSSM parameters from direct searches and from the WMAP satellite observations, the resulting predicted rate for $\overrightarrow{\mu }e\gamma$ in this model class can be within the current experimental bounds for low $\tan \beta ,$ but that the next generation of $\overrightarrow{\mu }e\gamma$ experiments would effectively rule out this model class if LFV is not detected.

We compute finite-size corrections to nucleon masses and magnetic moments in a periodic, spatial box of size L, both in QCD and in partially quenched QCD.

We explore the splitting between flavor singlet and non-singlet mesons in charmonium using unquenched lattice QCD. The non-perturbatively improved clover formalism is used for both the sea and valence quarks. This has implications for lattice calculations of the hyperfine splitting in charmonium.

Assuming the two-diquark structure for the pentaquark state as advocated in the Jaffe-Wilczek model, there exist exotic parity-even antisextet and parity-odd triplet heavy pentaquark baryons. The theoretical estimate of charmed and bottom pentaquark masses is quite controversial and it is not clear whether the ground-state heavy pentaquark lies above or below the strong-decay threshold. We study the weak transitions of heavy pentaquark states using the light-front quark model. In the heavy quark limit, heavy-to-heavy pentaquark transition form factors can be expressed in terms of three Isgur-Wise functions: two of them are found to be normalized to unity at zero recoil, while the third one is equal to 1/2 at the maximum momentum transfer, in accordance with the prediction of the large-$N_c$ approach or the quark model. Therefore, the light-front model calculations are consistent with the requirement of heavy quark symmetry. Numerical results are obtained for form factors and Isgur-Wise functions are presented. Decay rates of the weak decays ${\Theta }_b^{+}\to {\Theta }_c^0{\pi }^{+}\left({\rho }^{+}\right),$ ${\Theta }_c^0\to {\Theta }^{+}{\pi }^{-}\left({\rho }^{-}\right),$ ${\Sigma }_{5b}^{\prime +}\to {\Sigma }_{5c}^{\prime 0}{\pi }^{+}\left({\rho }^{+}\right),$ and ${\Sigma }_{5c}^{\prime 0}\to N_8^{+}{\pi }^{-}\left({\rho }^{-}\right)$ with ${\Theta }_Q,$ ${\Sigma }_{5Q}^{\prime },$ and $N_8$ being the heavy antisextet, heavy triplet, and light octet pentaquarks, respectively. For weakly decaying ${\Theta }_b^{+}$ and ${\Theta }_c^0,$ the branching ratios of ${\Theta }_b^{+}\to {\Theta }_c^0{\pi }^{+}$ and ${\Theta }_c^0\to {\Theta }^{+}{\pi }^{-}$ are estimated to be at the level of ${10}^{-3}$ and a few percent, respectively.

We study the rare decays $B^{+}\to D^{\left(*\right)+}{K}^{\left(*\right)0\mathrm{}},$ which can occur only via annihilation-type diagrams in the standard model. We calculate all of the four modes $\overrightarrow{B}PP,VP,PV,\mathrm{VV}$ in the framework of the perturbative QCD approach and give the branching ratios of the order about ${10}^{-6}.$

A model of independent pair parton interactions is proposed, according to which hadron interactions are represented by a set of independent binary parton collisions. The final multiplicity distribution is described by a convolution of the negative binomial distributions in each of the partonic collisions. As a result, it is given by a weighted sum of negative binomial distributions with parameters multiplied by the number of active pairs. Its shape and moments are considered. Experimental data on multiplicity distributions in high energy $p\overline{p}$ processes are well fitted by these distributions. Predictions for the CERN Large Hadron Collider and higher energies are presented. The difference between $e^{+}{e}^{-}$ and $p\overline{p}$ processes is discussed.

The positivity bounds on generalized parton distributions are derived from the positivity properties of the absorptive part of the amplitude of the virtual Compton scattering in the generalized Bjorken region.

We construct the spin-flavor wave functions of the possible heavy pentaquarks containing an anticharm or antibottom quark using various clustered quark models. Then we estimate the masses and magnetic moments of the $J^P={\frac{1}{2}}^{+}$ or ${\frac{3}{2}}^{+}$ heavy pentaquarks. We emphasize the difference in the predictions of these models. Future experimental searches at BESIII, CLEOc, BELLE, and LEP may find these interesting states.