We consider the growth of cosmological perturbations to the energy density of dark matter during matter domination when dark matter is a scalar field that has undergone Bose-Einstein condensation. We study these inhomogeneities within the framework of both Newtonian gravity, where the calculation and results are more transparent, and General Relativity. The direction we take is to derive analytical expressions, which can be obtained in the small pressure limit. Throughout we compare our results to those of the standard cosmology, where dark matter is assumed pressureless, using our analytical expressions to showcase precise differences. We find, compared to the standard cosmology, that Bose-Einstein condensate dark matter leads to a scale factor, gravitational potential and density contrast that increase at faster rates.

Models of inflation based on axions, which owe their popularity to the robustness against uv corrections, have also a very distinct class of signatures. The relevant interactions of the axion are a nonperturbative oscillating contribution to the potential and a shift-symmetric coupling to gauge fields. We review how these couplings affect the cosmological perturbations via a unified study based on the in-in formalism. We then note that, when the inflaton coupling to gauge fields is high enough to lead to interesting observational results, the backreaction of the produced gauge quanta on the inflaton dynamics becomes relevant during the final stage of inflation, and prolongs its duration by about 10 e-foldings. We extend existing results on gravity wave production in these models to account for this late inflationary phase. The strong backreaction phase results in an enhancement of the gravity wave signal at the scales of interferometers. As a consequence, the signal is potentially observable at interferometers such as Advanced LIGO/Virgo for the most natural duration of inflation in such models. Finally, we explicitly compute the axion couplings to gauge fields in string theory construction of axion-monodromy inflation and identify cases where they can trigger interesting phenomenological effects.

It has been shown that a contracting universe with a dustlike ($w\approx 0$) fluid may provide an almost scale invariant spectrum for the gravitational scalar perturbations. As the universe contracts, the amplitude of such perturbations are amplified. The gauge invariant variable $\Phi$ develops a growing mode which becomes much larger than the constant one around the bounce phase. The constant mode has its amplitude fixed by Cosmic Background Explorer (COBE) normalization, thus the amplitude of the growing mode can become much larger than $1$. In this paper, we first show that this is a general feature of bouncing models, since we expect that general relativity should be valid in all scales away from the bounce. However, in the Newtonian gauge, the variable $\Phi$ gives the value of the metric perturbation $\varphi$, raising doubts on the validity of the linear perturbative regime at the bounce. In order to address this issue, we obtain a set of necessary conditions for the perturbative series to be valid along the whole history of the model, and we show that there is a gauge in which all these conditions are satisfied, for a set of models, if the constant mode is fixed by COBE normalization. As a by-product of this analysis, we point out that there are sets of solutions for the perturbation variables where some gauge-fixing conditions are not well defined, turning these gauges prohibited for those solutions.

Bilinear $R$-parity violation provides an attractive origin for neutrino masses and mixings. In such schemes the gravitino is a viable decaying dark matter particle whose $R$-parity violating decays lead to monochromatic photons with rates accessible to astrophysical observations. We determine the parameter region allowed by gamma-ray line searches, dark matter relic abundance, and neutrino oscillation data, obtaining a limit on the gravitino mass $m_{\tilde{G}}\lesssim 1–10\mathrm{GeV}$ corresponding to a relatively low reheat temperature $T_R\lesssim \mathrm{\text{few}}\times {10}^7–{10}^8\mathrm{GeV}$. Neutrino mass and mixing parameters may be reconstructed at accelerator experiments like the Large Hadron Collider.

If quark stars exist, they may be enveloped in thin electron layers (electron seas), which uniformly surround the entire star. These layers will be affected by the magnetic fields of quark stars in such a way that the electron seas would transmit hydromagnetic cyclotron waves, as studied in this paper. Particular attention is devoted to vortex hydrodynamical oscillations of the electron sea. The frequency spectrum of these oscillations is derived in analytic form. If the thermal x-ray spectra of quark stars are modulated by vortex hydrodynamical vibrations, the thermal spectra of compact stars (foremost, central compact objects and x-ray dim isolated neutron stars) could be used to verify the existence of these vibrational modes observationally. The central compact object 1E 1207.4-5209 appears particularly interesting in this context, since its absorption features at 0.7 keV and 1.4 keV can be comfortably explained in the framework of the hydrocyclotron oscillation model.

We present the analytical formulas, derived based on the halo model, to compute the cross correlation between the thermal Sunyaev-Zel’dovich (SZ) effect and the distribution of galaxy clusters. By binning the clusters according to their redshifts and masses, this cross correlation, the so-called stacked SZ signal, reveals the average SZ profile around the clusters. The stacked SZ signal is obtainable from a joint analysis of an arc-minute–resolution cosmic microwave background (CMB) experiment and an overlapping optical survey, which allows for detection of the SZ signals for clusters whose masses are below the individual cluster detection threshold. We derive the error covariance matrix for measuring the stacked SZ signal, and then forecast for its detection from ongoing and forthcoming combined CMB-optical surveys. We find that, over a wide range of mass and redshift, the stacked SZ signal can be detected with a significant signal-to-noise ratio (total $S/N\gtrsim 10$), whose value peaks for the clusters with intermediate masses and redshifts. Our calculation also shows that the stacking method allows for probing the clusters’ SZ profiles over a wide range of scales, even out to projected radii as large as the virial radius, thereby providing a promising way to study gas physics at the outskirts of galaxy clusters.

We study some New Physics effects on the hadronic decays of the Top quark, like $t\to b\overline{b}c$, and on a forward-backward-like $CP$ even asymmetry $A_t$ constructed in such a way that it is zero in the standard model (SM). We find that an anomalous right-handed contribution of the effective $tbW$ vertex may induce an asymmetry $A_t$ of the order of 20%. A light $W^{\prime }$ boson with pure right-handed couplings $td{W}^{\prime }$ may induce an asymmetry $A_t$ of the same order of magnitude.

Modified neutrino dispersion relations, which still obey the relativity principle, can have both a superluminal (muon-type) neutrino and a luminal (electron-type) neutrino, as long as neutrino-mass effects can be neglected. The idea is to allow for flavor-dependent deformed Lorentz transformations and an appropriate hierarchy of energy scales. If OPERA’s result on a superluminal velocity of the muon-neutrino is confirmed, the model has a matching superluminal velocity of the corresponding charged lepton, the muon, at equal particle energy. Assuming that this model is not already ruled out, new TeV-scale effects in the muon sector are predicted. Also discussed is a different model with a superluminal sterile neutrino propagating in the usual 4 spacetime dimensions.

We present a method for cleanly extracting the $CP$ phase $\gamma$ from the Dalitz plots of $B^{+}\to K^{+}{\pi }^{+}{\pi }^{-}$, $B_d^0\to K^{+}{\pi }^0{\pi }^{-}$, $B_d^0\to K^0{\pi }^{+}{\pi }^{-}$, $B_d^0\to K^{+}{K}^0{K}^{-}$, and $B_d^0\to K^0{K}^0{\overline{K}}^0$. The $B\to K\pi \pi$ and $B\to KK\overline{K}$ decays are related by flavor SU(3) symmetry, but SU(3) breaking is taken into account. Most of the experimental measurements have already been made—what remains is a Dalitz-plot analysis of $B_d^0\to K^0{K}^0{\overline{K}}^0$ (or $B_d^0\to K_S{K}_S{K}_S$). We (very) roughly estimate the error on $\gamma$ to be $\sim 25\%$. This is somewhat larger than the error in two-body decays, but it would be the first clean measurement of $\gamma$ in three-body decays. Furthermore, at the super-$B$ factory, it is possible that $\gamma$ could be measured more precisely in three-body decays than in two-body decays.

In supersymmetric theories with a strong conformal sector, soft supersymmetry breaking naturally gives rise to confinement and chiral symmetry breaking in the strong sector at the TeV scale. We construct and analyze models where such a sector dynamically breaks electroweak symmetry, and take the first steps in studying their phenomenology. We consider two scenarios, one where the strong dynamics induces vacuum expectation values for elementary Higgs fields, and another where the strong dynamics is solely responsible for electroweak symmetry breaking. In both cases there is no fine-tuning required to explain the absence of a Higgs boson below the LEP bound, solving the supersymmetry naturalness problem. Quark and lepton masses arise from conventional Yukawa couplings to elementary Higgs bosons, so there are no additional flavor-changing effects associated with the strong dynamics. A good precision electroweak fit can be obtained because the strong sector is an $SU(2)$ gauge theory with one weak doublet, and has adjustable parameters that control the violation of custodial symmetry. In addition to the standard supersymmetry signals, these models predict production of multiple heavy standard model particles ($t$, $W$, $Z$, and $b$) from decays of resonances in the strong sector. The strong sector has no approximate parity symmetry, so $WW$ scattering is unitarized by states that can decay to $WWW$ as well as $WW$.

In the framework of the littlest Higgs model with T parity, we study the $W_H/Z_H$ production in association with a T-odd (anti)quark of the first two generations at the CERN Large Hadron Collider up to the QCD next-to-leading order. The kinematic distributions of final decay products and the theoretical dependence of the cross section on the factorization/renormalization scale are discussed. We apply three schemes in considering the QCD NLO contributions and find that the QCD NLO corrections by adopting the (II) and (III) subtraction schemes can keep the convergence of the perturbative QCD description and reduce the scale uncertainty of the leading order cross section. By using these two subtraction schemes, the QCD NLO corrections to the $W_H(Z_H)q_{-}$ production process enhance the leading order cross section with a K-factor in the range of $1.00\sim 1.43$.

We present a supersymmetric extension of the Sstandard model that possesses a continuous $U(1{)}_R$ symmetry, which is identified with one of three lepton numbers, and where a sneutrino vev gives mass to the down-type quark and leptons. This idea allows for a smaller particle content than the minimal $R$-symmetric supersymmetry extension of the standard model. We explore bounds on this model coming from electroweak precision measurements, neutrino masses, and gravitino decay. Bounds from electroweak precision measurements lead to a two-sided bound on $\tan \beta$, while gravitino decay forces a low reheating temperature. Finally, the generation of neutrino masses from $R$-symmetry violation put an upper bound on the SUSY-breaking scale. Despite all of this, we find that the allowed parameter space is still large and would lead to a distinctive phenomenology at the LHC.

Soft supersymmetry breaking appears in the weak-scale effective action but is usually generated at higher scales. For these models, the structure of the renormalization group evolution down to the electroweak scale leaves only part of the squark-gluino and slepton-gaugino mass planes accessible. Our observations divide these physical mass planes into three wedges: the first can be reached by all models of high-scale breaking; the second can only be populated by models with a low mediation scale; in the third, wedge squarks and gluinos would have to be described by an exotic theory. All usual benchmark points reside in the first wedge, even though an LHC discovery in the third wedge would arguably be the most exciting outcome.

This paper presents a combined analysis of the KARMEN and LSND ${\nu }_e$-carbon cross section measurements within the context of a search for ${\nu }_e$ disappearance at high $\Delta m^2$. KARMEN and LSND were located at 17.7 m and 29.8 m, respectively, from the neutrino source, so, the consistency of the two measurements, as a function of antineutrino energy, sets strong limits on neutrino oscillations. Most of the allowed region from the ${\nu }_e$ disappearance analysis of the Gallium calibration data is excluded at $>95\%$ CL and the best-fit point is excluded at $3.6\sigma$. Assuming $CPT$ conservation, comparisons are also made to the oscillation analyses of reactor antineutrino data.

We calculate the full spectrum, as observed today, of the cosmological gravitational waves generated within a model based on loop quantum cosmology, in which the corrections to the dynamical equations describing the evolution of the universe during the semiclassical regime are of the inverse-volume type. It is assumed that the universe, after the transition to the classical regime, undergoes a period of inflation driven by a scalar field with a chaotic-type potential. Our analysis shows that, for certain conditions, loop quantum effects leave a clear signature on the spectrum, namely, an overproduction of low-frequency gravitational waves. One of the aims of our work is to show that loop quantum cosmology models can be tested and that, more generally, preinflationary physical processes leave their imprint in gravitational-wave spectra and can also be tested.

In this paper, we investigate the null geodesics of the static-charged black hole in heterotic string theory. A detailed analysis of the geodesics are done in the Einstein frame as well as in the string frame. In the Einstein frame, the geodesics are solved exactly in terms of the Jacobi-elliptic integrals for all possible energy levels and angular momentum of the photons. In the string frame, the geodesics are presented for the circular orbits. As a physical application of the null geodesics, we have obtained the angle of deflection for the photons and the quasinormal modes of a massless scalar field in the eikonal limit.

The electroweak symmetry is nonlinearly realized in an extension of the minimal supersymmetric standard model (MSSM) through an additional pair of constrained Higgs doublet superfields. The superpotential couplings of this constrained Higgs doublet pair to the MSSM Higgs doublet pair catalyze their vacuum expectation values. The Higgs and Higgsino-gaugino mass spectrum is presented for several choices of supersymmetry breaking and Higgs superpotential mass parameters. The additional vacuum expectation values provided by the constrained fields can produce a phenomenology quite different than that of the MSSM.

If neutrinoless double beta decay is observed, it will be important to understand the mechanism(s) behind this process. Using a minimal supersymmetric extension to the standard model in association with a lepton number violating coupling as an example, we show that if neutrinoless double beta decay is mediated by new TeV scale particles, looking for four-jet final states in future linear colliders operating in the same-sign electron mode could provide important information on the underlying mechanisms. We study the prospects for observing this process at the proposed ILC and CLIC energies, and discuss the complementarity between such a four-jet signal and other collider signatures at the LHC.

Motivated by the desire to construct meson-meson operators of definite relative momentum in order to study resonances in lattice QCD, we present a set of single-meson interpolating fields at nonzero momentum that respect the reduced symmetry of a cubic lattice in a finite cubic volume. These operators follow from the subduction of operators of definite helicity into irreducible representations of the appropriate little groups. We show their effectiveness in explicit computations where we find that the spectrum of states interpolated by these operators is close to diagonal in helicity, admitting a description in terms of single-meson states of identified $J^{PC}$. The variationally determined optimal superpositions of the operators for each state give rapid relaxation in Euclidean time to that state, ideal for the construction of meson-meson operators and for the evaluation of matrix elements at finite momentum.