We show that the two-time physics model leads to a mechanical system with Dirac brackets consistent with the Snyder noncommutative space. A Euclidean version of this space is also obtained and it is shown that both spaces have a dual system describing a particle in a curved space.

Gamma-ray bursts (GRBs) are now considered as relativistic jets. We analyze the gravitational waves from the acceleration stage of the GRB jets. We show that (i) the point mass approximation is not appropriate if the opening half-angle of the jet is larger than the inverse of the Lorentz factor of the jet; (ii) the gravitational waveform has many step function like jumps, and (iii) the practical DECIGO and BBO may detect such an event if the GRBs occur in the Local Group. We found that the light curve of GRBs and the gravitational waveform are anticorrelated so that the detection of the gravitational wave is indispensable to determine the structure of GRB jets.

We present Keplerian-type parametrization for the solution of third post-Newtonian (3PN) accurate equations of motion for two nonspinning compact objects moving in an eccentric orbit. The orbital elements of the parametrization are explicitly given in terms of the 3PN accurate conserved orbital energy and angular momentum in both Arnowitt-Deser-Misner–type and harmonic coordinates. Our representation will be required to construct post-Newtonian accurate “ready to use” search templates for the detection of gravitational waves from compact binaries in inspiralling eccentric orbits. Because of the presence of certain 3PN accurate gauge invariant orbital elements, the parametrization should be useful to analyze the compatibility of general relativistic numerical simulations involving compact binaries with the corresponding post-Newtonian descriptions. If required, the present parametrization will also be needed to compute post-Newtonian corrections to the currently employed “timing formula” for the radio observations of relativistic binary pulsars.

We prove a theorem that characterizes a large family of nonstatic solutions to Einstein equations, representing, in general, spherically symmetric Type II fluid. It is shown that the best known dynamical black hole solutions to Einstein equations are particular cases from this family. Thus we extend a recent work of Salgado [12] to nonstatic case. The spherically symmetric static black hole solutions, for Type I fluid, are also retrieved.

The general formalism for calculating the Newtonian potential in fine-tuned or critical Randall-Sundrum braneworlds is outlined. It is based on using the full tensor structure of the graviton propagator. This approach avoids the brane-bending effect arising from calculating the potential for a point source. For a single brane, this gives a clear understanding of the disputed overall factor $4/3$ entering the correction. The result can be written on a compact form which is evaluated to high accuracy for both short and large distances.

In recent papers on the Randall-Sundrum D-braneworld model with $Z_2$ symmetry, it was shown that the effective gravity does not work as usual; that is, the gravity does not couple to the gauge field localized on the brane in the usual way. At first glance, there are two possibilities to avoid this serious problem. One is to remove the $Z_2$ symmetry and another is to consider a non-Bogomol'nyi-Prasad-Sommerfield (BPS) state. In this paper, we analyze the Randall-Sundrum D-braneworld model without $Z_2$ symmetry by long wave approximation. The result is an unexpected one; that is, the gauge field does not couple to the gravity on the brane in the leading order again. Therefore, the remaining possibility to recover the conventional gravitational theory would be non-BPS cases.

We present detailed numerical simulations of a laser phase stabilization scheme for Laser Interferometer Space Antenna (LISA), where both lasers emitting along one arm are locked to each other. Including the standard secondary noises and spacecraft motions that approximately mimic LISA’s orbit (excluding the rotation of the constellation), we verify that very stable laser phases can be obtained and that time delay interferometry can be used to remove the laser phase noise from measurements of gravitational wave strains. Most importantly, we show that this locking scheme can provide significant simplifications over LISA’s baseline design in the implementation of time delay interferometry.

The beam splitter in high-power interferometers is subject to significant radiation-pressure fluctuations. As a consequence, the phase relations which appear in the beam splitter coupling equations oscillate and phase modulation fields are generated which add to the reflected fields. In this paper, the transfer function of the various input fields impinging on the beam splitter from all four ports onto the output field is presented including radiation-pressure effects. We apply the general solution of the coupling equations to evaluate the input-output relations of the dual-recycled laser-interferometer topology of the gravitational-wave detector GEO 600 and the power-recycling, signal-extraction topology of advanced LIGO. We show that the input-output relation exhibits a bright-port dark-port coupling. This mechanism is responsible for bright port contributions to the noise density of the output field and technical laser noise is expected to decrease the interferometer’s sensitivity at low frequencies. It is shown quantitatively that the issue of technical laser noise is unimportant in this context if the interferometer contains arm cavities.

Recent, persistent discrepancies between theoretical and experimental values of the muon’s anomalous magnetic moment set some stringent limits on the violation of the discrete symmetries in rotational inertia. A simple model indicates that the violation is relatively stronger for positive helicity and that the interaction of rotation with spin can produce asymmetry in the Universe.

A predictive framework for fermion masses and mixing is given by the supersymmetric SO(10) model with one ${10}_H$, one ${\overline{126}}_H$, one ${126}_H$, and one ${210}_H$ Higgs representations, and type-II seesaw dominating the neutrino mass matrix. We investigate the origin of the tension between this model and lepton mixing data and refine previous numerical analyses. We discuss an extension of the minimal model that includes one ${120}_H$ chiral superfield representation. This exhausts the possible renormalizable contributions to the Yukawa sector. In spite of the increase in the number of parameters the predictivity of the minimal setting is not spoiled. We argue that the contributions to fermion masses due to the doublet components of ${120}_H$ can be naturally small compared to those of ${10}_H$ and $\overline{{126}_H}$, thus acting as a perturbation in the fermion mass generation. The antisymmetric nature of the ${120}_H$ Yukawa coupling affects at leading order the determination of the mixing angles and it allows to remove the inconsistencies between predictions and data on the neutrino parameters. An improvement in the experimental bound on $U_{e3}$ can tell this scenario from the minimal model.

A careful investigation of $1/m_b$ power-suppressed effects is crucial for enhancing predictive power of the QCD factorization approach to charmless $B$ decays. It is instructive to systematically investigate the $1/m_b$ effects from soft- and hard-gluon exchanges, in addition to annihilation topology in the charmless $B$ decays. In this work we try to give a systematic discussion on impact of such soft and hard exchanges on the penguin-dominated $B\to K\pi$ decays within the framework of the light-cone QCD sum rules (LCSR). For the weak phase $\gamma (=\mathrm{I}\mathrm{m}{V}_{ub}^{*})$ ranging from 40° to 80°, we find that because of the annihilation and soft and hard exchanges a numerical increase of 20–30% is expected in the branching ratios up to $\mathcal{O}(1/m_b^2)$ corrections; the resultant soft and hard corrections are less important than the annihilation contributions and amount only to a level of 10%. Possible sources of uncertainties are discussed in some details.

We present the results of a next-to-leading order analysis of single top production including the decay of the top quark. Radiative effects are included both in the production and the decay stages, using a general subtraction method. This calculation gives a good treatment of the jet activity associated with single top production. We perform an analysis of the single top search at the Tevatron, including a consideration of the main backgrounds, many of which are also calculated at next-to-leading order.

New, radiatively generated, next-to-leading (NLO) quark $(u,d,s,c,b)$ and gluon densities in a real, unpolarized photon are presented. We perform three global fits, based on the NLO Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations for $Q^2>1{\mathrm{G}\mathrm{e}\mathrm{V}}^2$, to all the available structure-function $F_2^{\gamma }(x,Q^2)$ data. As in our previous LO analysis we utilize two theoretical approaches. Two models, denoted as ${\mathrm{F}\mathrm{F}\mathrm{N}\mathrm{S}}_{\mathrm{C}\mathrm{J}\mathrm{K}}1$ and ${\mathrm{F}\mathrm{F}\mathrm{N}\mathrm{S}}_{\mathrm{C}\mathrm{J}\mathrm{K}}2$ NLO, adopt the so-called fixed flavor-number scheme for calculation of the heavy-quark contributions to $F_2^{\gamma }(x,Q^2)$; the Cornet-Jankowski-Krawczyk NLO model applies the $\mathrm{A}\mathrm{C}\mathrm{O}\mathrm{T}(\chi )$ scheme. We examine the results of our fits by a comparison with the LEP data for the $Q^2$ dependence of the $F_2^{\gamma }$, averaged over various $x$ regions, and the $F_{2,c}^{\gamma }$. Grid parametrizations of the parton densities for all fits are provided.

$K^{*}(892{)}^0{\overline{K}}^{*}(892{)}^0$ signals from ${\chi }_{cJ}(J=0,1,2)$ decays are observed for the first time using a data sample of 14 million $\psi (2S)$ events accumulated in the BES II detector. The branching fractions $\mathcal{B}[{\chi }_{cJ}\to K^{*}(892{)}^0{\overline{K}}^{*}(892{)}^0]$ $(J=0,1,2)$ are determined to be $(1.78\pm 0.34\pm 0.34)\times {10}^{-3}$, $(1.67\pm 0.32\pm 0.31)\times {10}^{-3}$, and $(4.86\pm 0.56\pm 0.88)\times {10}^{-3}$ for the ${\chi }_{c0}$, ${\chi }_{c1}$, and ${\chi }_{c2}$ decays, respectively, where the first errors are statistical and the second are systematic. The significances of these signals are about $4.7\sigma$, $4.5\sigma$, and $7.6\sigma$, respectively.

We present results of searches for $B$-meson decays to $K^{+}{\pi }^{-}{\pi }^{+}$ with the BABAR detector. With a data sample of $61.6\times {10}^6$ $B\overline{B}$ pairs, we measure the branching fractions and 90% confidence-level upper limits averaged over charge-conjugate states (the first error is statistical and the second is systematic): $\mathcal{B}[B^{+}\to K^{*0}(892){\pi }^{+}]=(15.5\pm {1.8}_{-4.0}^{+1.5})\times {10}^{-6}$, $\mathcal{B}[B^{+}\to f_0(980)K^{+},f_0\to {\pi }^{+}{\pi }^{-}]=(9.2\pm {1.2}_{-2.6}^{+2.1})\times {10}^{-6}$, $\mathcal{B}[B^{+}\to {\overline{D}}^0{\pi }^{+},{\overline{D}}^0\to K^{+}{\pi }^{-}]=(184.6\pm 3.2\pm 9.7)\times {10}^{-6}$, $\mathcal{B}[B^{+}\to {\rho }^0(770)K^{+}]<6.2\times {10}^{-6}$ and $\mathcal{B}[B^{+}\to K^{+}{\pi }^{-}{\pi }^{+}\mathrm{\text{nonresonant}}]<17\times {10}^{-6}$.

Abelian duality on the closed three-dimensional Riemannian manifold ${\mathcal{M}}^3$ is discussed. Partition functions for the ordinary U(1) gauge theory and a circle-valued scalar field theory on ${\mathcal{M}}^3$ are explicitly calculated and compared. It is shown that both theories are mutually dual.

We present a two-parameter family of AdS solutions to the two-dimensional type 0A effective action.

The Green-Schwarz action for a non-BPS $p=2$ brane embedded in a $N=1$, $D=4$ target superspace is shown to be equivalent to the Nambu-Goto-Akulov-Volkov action obtained via the nonlinear realization of the associated target space super-Poincaré symmetries. Introducing a U(1) gauge field strength as a Lagrange multiplier, this $p=2$ brane action is recast into its equivalent dual form non-BPS D2-brane Born-Infeld action. Following the procedure given by Sen, the Green-Schwarz action for a non-BPS D2-brane is determined directly. From it, conversely, the dual form non-BPS $p=2$ brane action is derived. The $p=2$ brane and the D2-brane actions obtained by these two approaches are different in form. Through explicitly determined field redefinitions, these actions are shown to be equivalent.

We analyze the Hawking(-Unruh) effect for a massive Dirac spinor on the ${\mathbb{Z}}_2$ quotient of Kruskal spacetime known as the ${\mathbb{R}\mathbb{P}}^3$ geon. There are two distinct Hartle-Hawking-like vacua, depending on the choice of the spin structure, and suitable measurements in the static region (which on its own has only one spin structure) distinguish these two vacua. However, both vacua appear thermal in the usual Hawking temperature to certain types of restricted operators, including operators with support in the asymptotic future (or past). Similar results hold in a family of topologically analogous flat spacetimes, where we show the two vacua to be distinguished also by the shear stresses in the zero-mass limit. As a by-product, we display the explicit Bogolubov transformation between the Rindler-basis and the Minkowski-basis for massive Dirac fermions in four-dimensional Minkowski spacetime.

This paper addresses the radiation back reaction problem for cosmological branes. A general framework is provided in which results are given for the radiation reaction with massless and massive scalar fields with flat extra dimensions and massless conformal fields in anti-de Sitter extra dimensions. For massless scalar field radiation, the back reaction terms in the equation of motion are nonanalytic. The interpretation of the radiation reaction terms is discussed and the equations of motion solved in simple cases. Nucleosynthesis bounds on dark radiation give a lower bound on the string vacuum energy scale of $\sqrt{A_T}{m}_p$, where $A_T$ is the tensor perturbation amplitude in the cosmic microwave background.