In this paper we investigate the potential of 3D cosmic shear to constrain massive neutrino parameters. We find that if the total mass is substantial (near the upper limits from large scale structure, but setting aside the Ly alpha limit for now), then 3D $\mathrm{\text{cosmic shear}}+\mathrm{\text{Planck}}$ is very sensitive to neutrino mass and one may expect that a next generation photometric redshift survey could constrain the number of neutrinos $N_{\nu }$ and the sum of their masses $m_{\nu }=\sum _i{m}_i$ to an accuracy of $\Delta N_{\nu }\sim 0.08$ and $\Delta m_{\nu }\sim 0.03\mathrm{eV}$, respectively. If in fact the masses are close to zero, then the errors weaken to $\Delta N_{\nu }\sim 0.10$ and $\Delta m_{\nu }\sim 0.07\mathrm{eV}$. In either case there is a factor 4 improvement over Planck alone. We use a Bayesian evidence method to predict joint expected evidence for $N_{\nu }$ and $m_{\nu }$. We find that 3D cosmic shear combined with a Planck prior could provide “substantial” evidence for massive neutrinos and be able to distinguish “decisively” between many competing massive neutrino models. This technique should “decisively” distinguish between models in which there are no massive neutrinos and models in which there are massive neutrinos with $|N_{\nu }-3|\gtrsim 0.35$ and $m_{\nu }\gtrsim 0.25\mathrm{eV}$. We introduce the notion of marginalized and conditional evidence when considering evidence for individual parameter values within a multiparameter model.

String theory, as well as the string inspired brane-world models such as the Randall-Sundrum (RS) one, suggest a modification of Newton’s law of gravitation at small distance scales. Search for modifications of standard gravity is an active field of research in this context. It is well known that short range corrections to gravity would violate the Newton-Birkhoff theorem. Based on calculations of RS-type non-Newtonian forces for finite size spherical bodies, we propose a torsion balance based experiment to search for the effects of violation of this theorem valid in Newtonian gravity as well as in the general theory of relativity. We explain the main principle behind the experiment and provide detailed calculations suggesting optimum values of the parameters of the experiment. The projected sensitivity is sufficient to probe the RS parameter up to 10 microns.

We study the complete set of flavor-changing hyperon axial-current matrix elements at small momentum transfer. Using partially quenched heavy baryon chiral perturbation theory, we derive the chiral and momentum behavior of the axial and induced pseudoscalar form factors. The meson pole contributions to the latter posses a striking signal for chiral physics. We argue that the study of hyperon axial matrix elements enables a systematic lattice investigation of the efficacy of three-flavor chiral expansions in the baryon sector. This can be achieved by considering chiral corrections to $SU(3)$ symmetry predictions, and their partially quenched generalizations. In particular, despite the presence of eight unknown low-energy constants, we are able to make next-to-leading order symmetry breaking predictions for two linear combinations of axial charges.

We reexamine whether $Z^{+}(4430)$ could be a $D_1^{\prime }-D^{*}$ or $D_1-D^{*}$ molecular state after considering both the pion and $\sigma$ meson exchange potentials and introducing the form factor to take into account the structure effect of the interaction vertex. Our numerical analysis with Matlab package MATSLISE indicates the contribution from the sigma meson exchange is small for the $D_1^{\prime }-D^{*}$ system and significant for the $D_1-D^{*}$ system. The S-wave $D_1-{\overline{D}}^{*}$ molecular state with only $J^P=0^{-}$ and $D_1^{\prime }-D^{*}$ molecular states with $J^P=0^{-},1^{-},2^{-}$ may exist with reasonable parameters. One should investigate whether the broad width of $D_1^{\prime }$ disfavors the possible formation of molecular states in the future. The bottom analog $Z_B$ of $Z^{+}(4430)$ has a larger binding energy, which may be searched at Tevatron and LHC. Experimental measurement of the quantum number of $Z^{+}(4430)$ may help uncover its underlying structure.

We investigate the pion and kaon (${\pi }^{+}$, $K^{+}$, $K^0$) electromagnetic form factors in the spacelike region: $Q^2\lesssim 1\mathrm{GeV}$, based on the gauged low-energy effective chiral action from the instanton vacuum in the large $N_c$ limit. Explicit flavor SU(3) symmetry breaking is taken into account. The nonlocal contributions turn out to be crucial to reproduce the experimental data. While the pion electromagnetic form factor is in good agreement with the data, the kaon one seems underestimated. We also calculate the electromagnetic charge radii for the pion and kaon: $⟨r^2{⟩}_{{\pi }^{+}}=0.455{\mathrm{fm}}^2$, $⟨r^2{⟩}_{K^{+}}=0.534{\mathrm{fm}}^2$, and $⟨r^2{⟩}_{K^0}=-0.060{\mathrm{fm}}^2$ without any adjustable free parameter except for the average instanton size and interinstanton distance, and they are compatible with the experimental data. The low-energy constant $L_9$ in the large $N_c$ limit is estimated to be $8.42\times {10}^{-3}$ from the pion charge radius.

The $X(3872)$ resonance is considered as a hadronic molecule, a loosely bound state of charmed $D^0$ and $D^{*0}$ mesons, since its mass is very close to the $D^{*0}{\overline{D}}^0$ threshold. Assuming structure and quantum numbers of $X(3872)$ as $(D^0{\overline{D}}^{*0}-D^{*0}{\overline{D}}^0)/\sqrt{2}$ and $J^{PC}=1^{++}$, we calculate the $X(3872)\to \gamma J/\psi$ decay width using a phenomenological Lagrangian approach. We also estimate the contribution of an additional $c\overline{c}$ component in the $X(3872)$ to this decay width, which is shown to be suppressed relative to the one of the molecular configuration.

We calculate the leading order corrections to the $\overline{B}\to X_s\gamma$ decay in the standard model with two large flat universal extra dimensions. We find that the contributions involving the exchange of Kaluza-Klein modes of the physical scalar field $a_{(kl)}^{\pm }$ depend logarithmically on the ultraviolet cutoff scale $\Lambda$. We emphasize that all flavor-changing neutral current transitions suffer from this problem. Although the ultraviolet sensitivity weakens the lower bound on the inverse compactification radius $1/R$ that follows from $\overline{B}\to X_s\gamma$, the constraint remains stronger than any other available direct measurement. After performing a careful study of the potential impact of cutoff and higher-order effects, we find $1/R>650\mathrm{GeV}$ at 95% confidence level if errors are combined in quadrature. Our limit is at variance with the parameter region $1/R\lesssim 600\mathrm{GeV}$ preferred by dark matter constraints.

Pions, like nucleons, are composed primarily of up and down quarks and gluons. Constraints on spin-independent Lorentz violation in the proton, neutron, and pion sectors translate into bounds on Lorentz violation for the fundamental fields. The best bounds on pion Lorentz violation come from astrophysical measurements. The absence of the absorption process $\gamma \to {\pi }^{+}+{\pi }^{-}$ for up to 50 TeV photons constrains the possibility that pions’ maximum achievable velocities are less than 1 at the $1.5\times {10}^{-11}$ level. The fact that pions with energies up to 30 TeV are observed to decay into photons rather than hadrons bounds the possibility of a maximum velocity greater than 1 at the $2\times {10}^{-9}$ level. This provides the first two-sided bounds on Lorentz violation for pions.

Binary black hole coalescence is treated semianalytically by a novel approach. Our prescription employs the conservative Skeleton Hamiltonian that describes orbiting Brill-Lindquist wormholes (termed punctures in numerical relativity) within a waveless truncation to the Einstein field equations [G. Faye, P. Jaranowski, and G. Schäfer, Phys. Rev. D 69, 124029 (2004)]. We incorporate, in a transparent Hamiltonian way and in Burke-Thorne gauge structure, the effects of gravitational radiation reaction into the above Skeleton dynamics with the help of 3.5PN accurate angular momentum flux for compact binaries in quasicircular orbits to obtain a semianalytic puncture evolution to model merging black hole binaries. With the help of the TaylorT4 approximant at 3.5PN order, we perform a first-order comparison between gravitational-wave phase evolutions in numerical relativity and our approach for equal-mass binary black holes. This comparison reveals that a modified Skeletonian reactive dynamics that employs flexible parameters will be required to prevent the dephasing between our scheme and numerical relativity, similar to what is pursued in the effective one-body approach. A rough estimate for the gravitational waveform associated with the binary black hole coalescence in our approach is also provided.

We present a new class of slowly rotating black hole solutions in $(n+1)$-dimensional $(n\ge 3)$ Einstein-Maxwell-dilaton gravity in the presence of Liouville-type potential for the dilaton field and an arbitrary value of the dilaton coupling constant. Because of the presence of the dilaton field, the asymptotic behavior of these solutions are neither flat nor (A)dS. In the absence of a dilaton field, our solution reduces to the $(n+1)$-dimensional Kerr-Newman modification thereof for small rotation parameter [A. N. Aliev, Phys. Rev. D 74, 024011 (2006).]. We also compute the angular momentum and the gyromagnetic ratio of these rotating dilaton black holes.

Charged Dirac particles’ Hawking radiation from a Kerr-Newman black hole is calculated using Damour-Ruffini’s method. When energy conservation and the backreaction of particles to the space-time are considered, the emission spectrum is not purely thermal anymore. The leading term is exactly the Boltzman factor, and the deviation from the purely thermal spectrum can bring some information out, which can be treated as an explanation to the information loss paradox. The result can also be treated as a quantum-corrected radiation temperature, which is dependent on the black hole background and the radiation particle’s energy, angular momentum, and charge.

Four-dimensional BF theory admits a natural coupling to extended sources supported on two-dimensional surfaces or string world sheets. Solutions of the theory are in one to one correspondence with solutions of Einstein equations with distributional matter (cosmic strings). We study new (topological field) theories that can be constructed by adding extra degrees of freedom to the two-dimensional world sheet. We show how two-dimensional Yang-Mills degrees of freedom can be added on the world sheet, producing in this way, an interactive (topological) theory of Yang-Mills fields with BF fields in four dimensions. We also show how a world sheet tetrad can be naturally added. As in the previous case the set of solutions of these theories are contained in the set of solutions of Einstein’s equations if one allows distributional matter supported on two-dimensional surfaces. These theories are argued to be exactly quantizable. In the context of quantum gravity, one important motivation to study these models is to explore the possibility of constructing a background-independent quantum field theory where local degrees of freedom at low energies arise from global topological (world sheet) degrees of freedom at the fundamental level.

Weak gravitational lensing by foreground density perturbations generates a gradient mode in the shear of background images. In contrast, cosmological tensor perturbations induce a nonzero curl mode associated with image rotations. In this note, we study the lensing signatures of both primordial gravitational waves from inflation and second-order gravitational waves generated from the observed spectrum of primordial density fluctuations. We derive the curl mode for galaxy lensing surveys at redshifts of 1–3 and for lensing of the cosmic microwave background at a redshift of 1100. We find that the curl mode angular power spectrum associated with secondary tensor modes for galaxy lensing surveys dominates over the corresponding signal generated by primary gravitational waves from inflation. However, both tensor contributions to the shear curl mode spectrum are below the projected noise levels of upcoming galaxy and cosmic microwave background lensing surveys and therefore are unlikely to be detectable.

After commenting briefly on the role of the typicality assumption in science, we advocate a phenomenological approach to the cosmological measure problem. Like any other theory, a measure should be simple, general, well defined, and consistent with observation. This allows us to proceed by elimination. As an example, we consider the proper time cutoff on a geodesic congruence. It predicts that typical observers are quantum fluctuations in the early universe, or Boltzmann babies. We sharpen this well-known youngness problem by taking into account the expansion and open spatial geometry of pocket universes. Moreover, we relate the youngness problem directly to the probability distribution for observables, such as the temperature of the cosmic background radiation. We consider a number of modifications of the proper time measure, but find none that would make it compatible with observation.

It is likely that ultrahigh energy cosmic rays contain a significant component of heavy or intermediate mass nuclei. The propagation of ultrahigh energy nuclei through cosmic radiation backgrounds is more complicated than that of protons and its study has required the use of Monte Carlo techniques. We present an analytic method for calculating the spectrum and the composition at Earth of ultrahigh energy cosmic rays which start out as heavy nuclei from their extragalactic sources. The results obtained are in good agreement with those obtained using numerical methods.

We show how to constrain the physical spectrum of walking technicolor models via precision measurements and modified Weinberg sum rules. We also study models possessing a custodial symmetry for the $S$ parameter at the effective Lagrangian level—custodial technicolor—and argue that these models cannot emerge from walking-type dynamics. We suggest that it is possible to have a very light spin-one axial (vector) boson. However, in the walking dynamics the associated vector boson is heavy while it is degenerate with the axial in custodial technicolor.

We investigate the phase diagram of strongly interacting matter as a function of temperature and baryonic density/chemical potential, within Nambu–Jona-Lasinio type models. We perform a systematic study concerning the existence, location, and properties of a critical end point/tricritical point, both in SU(2) and SU(3) versions of the model. We verify that, for $m_u=m_d=0$ and up to a critical strange quark mass, there is a tricritical point, which becomes a critical end point in a world with realistic values of the current quark masses. The properties of physical observables, such as the baryon number susceptibility and the specific heat, are analyzed in the vicinity of the critical end point, with special focus on their critical exponents. The behavior of mesons in the $T-{\mu }_B({\rho }_B)$ plane is analyzed in connection with possible signatures of partial and effective restoration of chiral symmetry.

Recently, a conceptually new physics beyond the standard model (SM), unparticle, has been proposed, where a hidden conformal sector is coupled to the SM sector through higher dimensional operators. In this setup, we investigate unparticle physics at the photon collider, in particular, unparticle effects on the $\gamma \gamma \to \gamma \gamma$ process. Since this process occurs at loop level in the SM, the unparticle effects can be significant even if the cutoff scale is very high. In fact, we find that the unparticle effects cause sizable deviations from the SM results. The scaling dimension of the unparticle $d_{\mathcal{U}}$ reflects the dependence of the cross section on the final state photon invariant mass, so that precision measurements of this dependence may reveal the scaling dimension of the unparticle.

We analyze the quark-gluon induced process $ug\to \tilde{d}{\tilde{\chi }}_i^{+}$, including the one-loop electroweak effects in the minimal supersymmetric model. This process is dominated by ${\tilde{d}}_L$-production and is determined by four helicity amplitudes, three of which are violating helicity conservation, and another one which respects it and is logarithmically enhanced at high energy. Combining this $ug\to {\tilde{d}}_L{\tilde{\chi }}_i^{+}$ analysis with a corresponding one for $ug\to d{W}^{+}$, we obtain simple approximate relations between the two processes, testing the minimal supersymmetric model structure at the amplitude and the cross section levels. These relations become exact at asymptotic energies and, provided the supersymmetry (SUSY) scale is not too heavy, they may be approximately correct at LHC energies also. In addition to these, we study the one-loop electroweak corrections to the inclusive $\tilde{d}{\tilde{\chi }}_i^{+}$ production at LHC, presenting as examples, the $p_T$ and angular distributions. Comparing these to the corresponding predictions for $W+\mathrm{\text{jet}}$ production derived earlier, provides an accurate test of the supersymmetric assignments.

There are some indications from recent determinations of the strong coupling constant ${\alpha }_s$ and the gluon condensate that the operator product expansion may not be accurate enough to describe nonperturbative effects in hadronic tau decays. This breakdown of the operator product expansion is usually referred to as being due to “duality violations.” With the help of a physically motivated model, we investigate these duality violations. Based on this model, we argue how they may introduce a non-negligible systematic error in the current analysis, which employs finite-energy sum rules with pinched weights. In particular, this systematic effect might affect the precision determination of ${\alpha }_s$ from tau decays. With a view to a possible future application to real data, we present an alternative method for determining the operator product expansion coefficients that might help with estimating, and possibly even reducing, this systematic error.