We solve Einstein equations on the brane to derive the exact form of the brane-world-corrected perturbations in Kerr-Newman singularities, using Randall-Sundrum and Arkani-Hamed-Dimopoulos-Dvali (ADD) models. It is a consequence of such models that Kerr-Newman mini-black holes can be produced in LHC. We use this approach to derive a normalized correction for the Schwarzschild Myers-Perry radius of a static $(4+n)$-dimensional mini-black hole, using more realistic approaches arising from Kerr-Newman mini-black hole analysis. Besides, we prove that there are four Kerr-Newman black hole horizons in the brane-world scenario we use, although only the outer horizon is relevant in the physical measurable processes. Parton cross sections in LHC and Hawking temperature are also investigated as functions of Planck mass (in the LHC range 1–10 TeV), mini-black hole mass, and the number of large extra dimensions in brane-world large extra-dimensional scenarios. In this case a more realistic brane-effect-corrected formalism can achieve more precisely the effective extra-dimensional Planck mass and the number of large extra dimensions—in the Arkani-Hamed-Dimopoulos-Dvali model—or the size of the warped extra dimension—in Randall-Sundrum formalism.

The charm and beauty quark production in deep inelastic scattering at low values of the Bjorken variable $x$ is considered in the DGLAP improved saturation model. After fitting parameters of the model to the structure function $F_2$, the heavy quark contributions $F_2^{c\overline{c}}$ and $F_2^{b\overline{b}}$ are predicted. A good description of the data is found. Predictions for the longitudinal structure function $F_L$ and the diffractive structure function $F_2^D$ are also presented.

In this paper we continue analysis of the Matrix theory describing the DLCQ of type IIB string theory on ${\mathrm{AdS}}_5\times S^5$ (and/or the plane-wave) background, i.e. the tiny graviton matrix theory (TGMT) [M. M. Sheikh-Jabbari, J. High Energy Phys. 09 (2004) 017.]. We study and classify $1/2$, $1/4$, and $1/8$ BPS solutions of the TGMT which are generically of the form of rotating three-brane giants. These are branes whose shape are deformed three-spheres and hyperboloids. In lack of a classification of such ten-dimensional type IIb supergravity configurations, we focus on the dual $\mathcal{N}=4$ four-dimensional $1/2$, $1/4$, and one $1/8$ BPS operators and show that they are in one-to-one correspondence with the states of the same set of quantum numbers in TGMT. This provides further evidence in support of the matrix theory.

By a suitable transformation, we present the $(n+1)$-dimensional charged rotating solutions of Gauss-Bonnet gravity with a complete set of allowed rotation parameters which are real in the whole spacetime. We show that these charged rotating solutions present black hole solutions with two inner and outer event horizons, extreme black holes, or naked singularities provided the parameters of the solutions are chosen suitable. Using the surface terms that make the action well defined for Gauss-Bonnet gravity and the counterterm method for eliminating the divergences in action, we compute finite action of the solutions. We compute the conserved and thermodynamical quantities through the use of free energy and the counterterm method, and find that the two methods give the same results. We also find that these quantities satisfy the first law of thermodynamics. Finally, we perform a stability analysis by computing the heat capacity and the determinant of Hessian matrix of mass with respect to its thermodynamic variables in both the canonical and the grand-canonical ensembles, and show that the system is thermally stable. This is commensurate with the fact that there is no Hawking-Page phase transition for black objects with zero curvature horizon.

We present evidence of a large angle correlation between the cosmic microwave background measured by WMAP and a catalog of photometrically detected quasars from the SDSS. The observed cross correlation is $0.30\pm 0.14\mu \mathrm{K}$ at zero lag, with a shape consistent with that expected for correlations arising from the integrated Sachs-Wolfe effect. The photometric redshifts of the quasars are centered at $z\sim 1.5$, making this the deepest survey in which such a correlation has been observed. Assuming this correlation is due to the ISW effect, this constitutes the earliest evidence yet for dark energy and it can be used to constrain exotic dark energy models.

We study the single field slow-roll inflation models that better agree with the available CMB and LSS data including the three years WMAP data: new inflation and hybrid inflation. We study these models as effective field theories in the Ginsburg-Landau context: a trinomial potential turns out to be a simple and well motivated model. The spectral index $n_s$ of the adiabatic fluctuations, the ratio $r$ of tensor to scalar fluctuations and the running index $d{n}_s/d\ln k$ are studied in detail. We derive explicit formulas for $n_s$, $r$ and $d{n}_s/d\ln k$ and provide relevant plots. In new inflation, and for the chosen central value $n_s=0.95$, we predict $0.03<r<0.04$ and $-0.00070<d{n}_s/d\ln k<-0.00055$. In hybrid inflation, and for $n_s=0.95$, we predict $r\simeq 0.2$ and $d{n}_s/d\ln k\simeq -0.001$. Interestingly enough, we find that in new inflation $n_s$ is bounded from above by $n_{s\max }=0.961528\dots$ and that $r$ is a two valued function of $n_s$ in the interval $0.96<n_s<n_{s\max }$. In the first branch we find $r<r_{\max }=0.114769\dots$. In hybrid inflation we find a critical value ${\mu }_{0\mathrm{crit}}^2$ for the mass parameter ${\mu }_0^2$ of the field $\sigma$ coupled to the inflaton. For ${\mu }_0^2<{\Lambda }_0{M}_{\mathrm{Pl}}^2/192$, where ${\Lambda }_0$ is the cosmological constant, hybrid inflation yields a blue tilted $n_s>1$ behavior. Hybrid inflation for ${\mu }_0^2>{\Lambda }_0{M}_{\mathrm{Pl}}^2/192$ fulfills all the present $\mathrm{CMB}+\mathrm{LSS}$ data for a large enough initial inflaton amplitude. Even if chaotic inflation predicts $n_s$ values compatible with the data, chaotic inflation is disfavored since it predicts a too high value $r\simeq 0.27$ for the ratio of tensor to scalar fluctuations. The model which best agrees with the current data and which best prepares the way to the expected data $r\lesssim 0.1$, is the trinomial potential with negative mass term: new inflation.

We extend previous work showing that violation of the null energy condition implies instability in a broad class of models, including gauge theories with scalar and fermionic matter as well as any perfect fluid. Simple examples are given to illustrate these results. The role of causality in our results is discussed. Finally, we extend the fluid results to more general systems in thermal equilibrium. When applied to the dark energy, our results imply that $w=p/\rho$ is unlikely to be less than $-1$.

We offer a method of calculating the source term in the line-of-sight integral for cosmic microwave background anisotropies without using a truncated partial-wave expansion in the Boltzmann hierarchy.

We extend the chiral Lagrangian with heavy quark-diquark symmetry to quenched and partially quenched theories. These theories are used to derive formulas for the chiral extrapolation of masses and hyperfine splittings of double heavy baryons in lattice QCD simulations. A quark-diquark symmetry prediction for the hyperfine splittings of heavy mesons and doubly heavy baryons is rather insensitive to chiral corrections in both quenched and partially quenched QCD. Extrapolation formulas for the doubly heavy baryon electromagnetic transition moments are also determined for the partially quenched theory.

In this paper we study the angular distribution of the rare $B$-decay $B\to K_2^{*}(\to K\pi )l^{+}{l}^{-}$, which is expected to be observed soon. We use the standard effective Hamiltonian approach, and use the form factors that have already been estimated for the corresponding radiative decay $B\to K_2^{*}\gamma$. The additional form factors that come into play for the dileptonic channel are estimated using the large energy effective theory (LEET), which enables one to relate the additional form factors to the form factors for the radiative mode. Our results provide, just like in the case of the $K^{*}(892)$ resonance, an opportunity for a straightforward comparison of the basic theory with experimental results, which may be expected in the near future for this channel.

Within a nonlinear chiral Lagrangian framework, the correlations between the quark and glueball admixtures of the isosinglet scalar mesons below 2 GeV and the current large uncertainties on the masses of $f_0(600)$ and $f_0(1370)$ are studied. The framework is formulated in terms of two scalar meson nonets (a two-quark nonet and a four-quark nonet) together with a scalar glueball. It is shown that, while some properties of these states are sensitive to the masses of $f_0(600)$ and $f_0(1370)$, several relatively robust conclusions can be made: $f_0(600)$, $f_0(980)$, and $f_0(1370)$ are admixtures of two- and four-quark components, with $f_0(600)$ being dominantly a nonstrange four-quark state, and $f_0(980)$ and $f_0(1370)$ having a dominant two-quark component. Similarly, $f_0(1500)$ and $f_0(1710)$ have considerable two- and four-quark admixtures, but in addition they have a large glueball component. For each state, a detailed analysis providing the numerical estimates of all components is given. It is also shown that this framework clearly favors the experimental values: $m^{\mathrm{expt}}[f_0(600)]<700\mathrm{MeV}$ and $m^{\mathrm{expt}}[f_0(1370)]=1300–1450\mathrm{MeV}$. Moreover, an overall fit to the available data shows a reciprocal substructure for $f_0(600)$ and $f_0(1370)$, and a linear correlation between their masses of the form $m[f_0(1370)]=0.29m[f_0(600)]+1.22\mathrm{GeV}$. The scalar glueball mass of 1.5–1.7 GeV is found in this analysis.

$P$-wave pentaquarks with strangeness $+1$, $I=0$, and $J^P=1/2^{+}$ are studied in the nonrelativistic quark model with instanton induced interaction (III). We present their mass splittings and orbital-spin-isospin-color structures. It is found that decompositions of the wave functions are sensitive to III, while the mass splittings are insensitive. The decay of the lowest energy pentaquark, ${\Theta }^{+}$, is found to be suppressed when the contribution of III is increased. Spin structure of the dominant components of the wave function is studied.

Two-body Dirac equations of constraint dynamics provide a covariant framework to investigate the problem of highly relativistic quarks in meson bound states. This formalism eliminates automatically the problems of relative time and energy, leading to a covariant three dimensional formalism with the same number of degrees of freedom as appears in the corresponding nonrelativistic problem. It provides bound state wave equations with the simplicity of the nonrelativistic Schrödinger equation. Here we begin important tests of the relativistic 16 component wave function solutions obtained in a recent work on meson spectroscopy, extending a method developed previously for positronium decay into two photons. Preliminary to this we examine the positronium decay in the ${}^{3}P_{0,2}$ states as well as the ${}^{1}S_0$. The two-gamma quarkonium decays that we investigate are for the ${\eta }_c$, ${\eta }_c^{\prime }$, ${\chi }_{c0}$, ${\chi }_{c2}$, ${\pi }^0$, ${\pi }_2$, $a_2$, and $f_2^{\prime }$ mesons. Our results for the four charmonium states compare well with those from other quark models and show the particular importance of including all components of the wave function as well as strong and c.m. energy dependent potential effects on the norm and amplitude. The results for the ${\pi }^0$, although off the experimental rate by 13%, are much closer than the usual expectations from a potential model. We conclude that the two-body Dirac equations lead to wave functions which provide good descriptions of the two-gamma decay amplitude and can be used with some confidence for other purposes.

We develop the minimal model of a new leading order parametrization of generalized parton distributions (GPDs) introduced by Polyakov and Shuvaev. The model for GPDs $H$ and $E$ is formulated in terms of the forward quark distributions, the Gegenbauer moments of the $D$-term, and the forward limit of the GPD $E$. The model is designed primarily for small and medium-size values of $x_B$, $x_B\le 0.2$. We examine two different models of the $t$ dependence of the GPDs: the factorized exponential model and the nonfactorized Regge-motivated model. Using our model, we successfully described the deeply virtual Compton scattering (DVCS) cross section measured by H1 and ZEUS, the moments of the beam-spin $A_{\mathrm{LU}}^{\sin \varphi }$, the beam-charge $A_C^{\cos \varphi }$, and the transversely polarized target $A_{\mathrm{UT}}^{\sin \phi \cos \varphi }$ DVCS asymmetries measured by HERMES and $A_{\mathrm{LU}}^{\sin \varphi }$ measured by CLAS. The data on $A_C^{\cos \varphi }$ prefer the Regge-motivated model of the $t$ dependence of the GPDs. The data on $A_{\mathrm{UT}}^{\sin \phi \cos \varphi }$ indicate that the $u$ and $d$ quarks carry only a small fraction of the proton total angular momentum.

We present a comparative analysis of chiral quark models which include nonlocal covariant four-fermion couplings. We consider two alternative ways of introducing the nonlocality, as well as various shapes for the momentum-dependent form factors governing the effective interactions. In all cases we study the behavior of model parameters and analyze numerical results for constituent quark masses and quark propagator poles. Advantages of these covariant nonlocal schemes over instantaneous nonlocal schemes and the standard NJL model are pointed out.

In this work we study a nonlinear gauged $\mathrm{O}(3)\mathrm{\text{−}}\sigma$ model with both minimal and nonminimal coupling in the covariant derivative. Using an asymmetric scalar potential, the model is found to exhibit both topological and nontopological soliton solutions in the Bogomol’nyi limit.

We find a class of four dimensional deformed conformal field theories which appear extra dimensional when their gauge symmetries are spontaneously broken. The theories are supersymmetric moose models which flow to interacting conformal fixed points at low energies, deformed by superpotentials. Using $a$-maximization we give strong nonperturbative evidence that the hopping terms in the resulting latticized action are relevant deformations of the fixed-point theories. These theories have an intricate structure of RG flows between conformal fixed points. Our results suggest that at the stable fixed points each of the bulk gauge couplings and superpotential hopping terms is turned on, in favor of the extra-dimensional interpretation of the theory. However, we argue that the higher-dimensional gauge coupling is generically small compared to the size of the extra dimension. In the presence of a brane the topology of the extra dimension is determined dynamically and depends on the numbers of colors and bulk and brane flavors, which suggests phenomenological applications. The RG flows between fixed points in these theories provide a class of tests of Cardy’s conjectured $a$-theorem.

Spherically symmetric static empty space solutions are studied in $f(R)$ theories of gravity. We reduce the set of modified Einstein’s equations to a single equation and show how one can construct exact solutions in different $f(R)$ models. In particular, we show that for a large class models, including e.g. the $f(R)=R-{\mu }^4/R$ model, the Schwarzschild-de Sitter metric is an exact solution of the field equations. The significance of these solutions is discussed in light of solar system constraints on $f(R)$ theories of gravity.

Loops formed from a cosmic string network at early times would act as seeds for early formation of halos, which would form galaxies and lead to early reionization. With reasonable guesses about astrophysical and string parameters, the cosmic string scale $G\mu$ must be no more than about $3\times {10}^{-8}$ to avoid conflict with the reionization redshift found by WMAP. The bound is much stronger for superstring models with a small string reconnection probability. For values near the bound, cosmic string loops may explain the discrepancy between the WMAP value and theoretical expectations.

Type Ia Supernovae are standard candles so their mean apparent magnitude has been exploited to learn about the redshift-distance relationship. Besides intrinsic scatter in this standard candle, additional scatter is caused by gravitational magnification by large scale structure. Here we probe the dependence of this dispersion on cosmological parameters and show that information about the amplitude of clustering, ${\sigma }_8$, is contained in the scatter. In principle, it will be possible to constrain ${\sigma }_8$ to within 5% with observations of 2000 Type Ia Supernovae. We identify three sources of systematic error—evolution of intrinsic scatter, baryon contributions to lensing, and non-Gaussianity of lensing—which will make this measurement difficult.