We discuss the emergence of an inflationary phase in supergravity with the super-Higgs effect due to dynamical spontaneous breaking of supersymmetry, in which the role of the inflaton is played by the gravitino condensate. Realistic models compatible with the Planck satellite cosmic microwave background data are found in conformal supergravity scenarios with dynamical gravitino masses that are small compared to the Planck mass, as could be induced by a nontrivial vacuum expectation value of the dilaton superfield of appropriate magnitude.

We discuss how internal rotation with fixed angular frequency can affect the solitons in the baby Skyrme model in which the global $O(3)$ symmetry is broken to the $SO(2)$. Two particular choices of the potential term are considered, the “old” potential and the “new” double vacuum potential, We do not impose any assumptions about the symmetry on the fields. Our results confirm existence of two types of instabilities determined by the relation between the mass parameter of the potential $\mu$ and the angular frequency $\omega$. It is shown that multi-Skyrmions in the model with old potential at some critical value of the angular frequency become unstable with respect to decay into single Skyrmion constituents.

The one-loop 3-point vertex functions of QCD in the maximal Abelian gauge are evaluated at the fully symmetric point at one loop. As a consequence the theory is renormalized in the various momentum subtraction schemes, which are defined by the trivalent vertices, as well as in the $\overline{\mathrm{MS}}$ scheme. From these the two-loop renormalization group functions in the momentum schemes are derived using the one-loop conversion functions. In parallel we repeat the analysis for the Curci–Ferrari gauge, which corresponds to the maximal Abelian gauge in a specific limit. The relation between the $\Lambda$ parameters in different schemes is also provided.

At the beginning of binary black hole simulations, there is a pulse of spurious radiation (or junk radiation) resulting from the initial data not matching astrophysical quasi-equilibrium inspiral exactly. One traditionally waits for the junk radiation to exit the computational domain before taking physical readings, at the expense of throwing away a segment of the evolution, and with the hope that junk radiation exits cleanly. We argue that this hope does not necessarily pan out, as junk radiation could excite long-lived constraint violation. Another complication with the initial data is that they contain orbital eccentricity that needs to be removed, usually by evolving the early part of the inspiral multiple times with gradually improved input parameters. We show that this procedure is also adversely impacted by junk radiation. In this paper, we do not attempt to eliminate junk radiation directly, but instead tackle the much simpler problem of ameliorating its long-lasting effects. We report on the success of a method that achieves this goal by combining the removal of junk radiation and eccentricity into a single procedure. Namely, we periodically stop a low resolution simulation; take the numerically evolved metric data and overlay it with eccentricity adjustments; run it through an initial data solver (i.e. the solver receives as free data the numerical output of the previous iteration); restart the simulation; repeat until eccentricity becomes sufficiently low; and then launch the high resolution “production run” simulation. This approach has the following benefits: (1) We do not have to contend with the influence of junk radiation on eccentricity measurements for later iterations of the eccentricity reduction procedure. (2) We reenforce constraints every time the initial data solver is invoked, removing the constraint violation excited by junk radiation previously. (3) The wasted simulation segment associated with the junk radiation’s evolution is absorbed into the eccentricity reduction iterations. Furthermore, (1) and (2) together allow us to carry out our joint-elimination procedure at low resolution, even when the subsequent “production run” is intended as a high resolution simulation.

The growth index ${\gamma }_L$ was proposed to investigate the possible deviation from the standard $\Lambda \mathrm{CDM}$ model and Einstein’s gravity theory in a dynamical perspective. Recently, thanks to the measurement of the cosmic growth rate via the redshift-space distortion, one can understand the evolution of the density contrast through $f{\sigma }_8(z)$, where $f(z)=d\ln \delta /d\ln a$ is the growth rate of matter and ${\sigma }_8(z)$ is the rms amplitude of the density contrast $\delta$ at the comoving $8h^{-1}\mathrm{Mpc}$ scale. In this paper, we use the redshift-space distortion data points to study the growth index on the bases of Einstein’s gravity theory and a modified gravity theory under the assumption of $f={\Omega }_m(a{)}^{{\gamma }_L}$. The cosmic background evolution is fixed by the cosmic observations from the type Ia supernovae SNLS3 data, cosmic microwave background radiation data from Planck, and baryon acoustic oscillations. Via the Markov Chain Monte Carlo method, we find the following ${\gamma }_L$ values for Einstein’s gravity with a cosmological constant ($w=\mathrm{const}$) dark energy and a modified gravity theory in the 1, 2, and $3\sigma$ regions, respectively: ${0.675}_{-0.0662-0.120-0.155}^{+0.0611+0.129+0.178}$, ${0.745}_{-0.0819-0.146-0.190}^{+0.0755+0.157+0.205}$, and ${0.555}_{-0.0167-0.0373-0.0516}^{+0.0193+0.0335+0.0436}$. In Einstein’s gravity theory, the values of the growth index ${\gamma }_L$ show an almost $2\sigma$ deviation from the theoretical prediction of $6/11$ for the $\Lambda \mathrm{CDM}$ model. However, in the modified gravity framework, a deviation from Einstein’s relativity is not detected in the $1\sigma$ region. This implies that the currently available cosmic observations do not predict an alternative modified gravity theory beyond the $\Lambda \mathrm{CDM}$ model under Einstein’s gravity, but that the simple assumption of $f={\Omega }_m^{{\gamma }_L}$ should be improved.

Binary black hole simulations with black hole excision using spectral methods require a coordinate transformation into a corotating coordinate system where the black holes are essentially at rest. This paper presents and discusses two coordinate transformations that are applicable to precessing binary systems, one based on Euler angles, the other on quaternions. Both approaches are found to work well for binaries with moderate precession, i.e., for cases where the orientation of the orbital plane changes by $\ll 90°$. For strong precession, performance of the Euler-angle parametrization deteriorates, eventually failing for a 90° change in orientation because of singularities in the parametrization (“gimbal lock”). In contrast, the quaternion representation is invariant under an overall rotation and handles any orientation of the orbital plane as well as the Euler-angle technique handles nonprecessing binaries.

We study the field equations of extensions of general relativity formulated within a metric-affine formalism setting torsion to zero (Palatini approach). We find that different (second-order) dynamical equations arise depending on whether torsion is set to zero (i) a priori or (ii) a posteriori, i.e., before or after considering variations of the action. Considering a generic family of Ricci-squared theories, we show that in both cases the connection can be decomposed as the sum of a Levi-Cività connection and terms depending on a vector field. However, while in case (i) this vector field is related to the symmetric part of the connection, in (ii) it comes from the torsion part and, therefore, it vanishes once torsion is completely removed. Moreover, the vanishing of this torsion-related vector field immediately implies the vanishing of the antisymmetric part of the Ricci tensor, which therefore plays no role in the dynamics. Related to this, we find that the Levi-Cività part of the connection is due to the existence of an invariant volume associated with an auxiliary metric $h_{\mu \nu }$, which is algebraically related with the physical metric $g_{\mu \nu }$.

We use N-body simulations to study the statistics of massive halos and redshift space distortions for theories with a standard $\Lambda \mathrm{CDM}$ expansion history and a Galileon-type scalar field. The extra scalar field increases the gravitational force, leading to enhanced structure formation. We compare our measurements of the real space matter power spectrum and halo properties with fitting formula for estimating these quantities analytically. We find that a model for power spectrum, halo mass function, and halo bias, derived from $\Lambda \mathrm{CDM}$ simulations, can fit the results from our simulations of modified gravity when ${\sigma }_8$ is appropriately adjusted. We also study the redshift space distortions in the two point correlation function measured from these simulations, finding a difference in the ratio of the redshift space to real space clustering amplitude relative to standard gravity on all scales. We find enhanced clustering on scales $r>10\mathrm{Mpc}/h$ and increased damping of the correlation function for scales $r<9\mathrm{Mpc}/h$. The boost in the clustering on large scales due to the enhanced gravitational forces cannot be mimicked in a standard gravity model by simply changing ${\sigma }_8$. This result illustrates the usefulness of redshift space distortion measurements as a probe of modifications to general relativity.

We investigate the possible accuracy that can be reached by analytical models for the matter density power spectrum and correlation function. Using a realistic description of the power spectrum that combines perturbation theory with a halo model, we study the convergence rate of several perturbative expansion schemes and the impact of nonperturbative effects, as well as the sensitivity to phenomenological halo parameters. We check that the simple reorganization of the standard perturbative expansion, with a Gaussian damping prefactor, provides a well-ordered convergence and a finite correlation function that yields a percent accuracy at the baryon acoustic oscillation peak (as soon as one goes to second order). Lagrangian-space expansions are somewhat more efficient, when truncated at low orders, but may diverge at high orders. We find that whereas the uncertainty on the halo-profile mass-concentration relation is not a strong limitation, the uncertainty on the halo mass function can severely limit the accuracy of theoretical predictions for $P(k)$ (this also applies to the power spectra measured in numerical simulations). The real-space correlation function provides a better separation between perturbative and nonperturbative effects, which are restricted to $x\lesssim 10h^{-1}\mathrm{Mpc}$ at all redshifts.

We use cosmological perturbation theory to study the backreaction effects of a self-consistent and well-defined cosmological averaging on the dynamics and the evolution of the Universe. Working with a perturbed Friedman-Lemaître-Robertson-Walker Einstein–de Sitter cosmological solution in a comoving volume-preserving gauge, we compute the expressions for the expansion scalar and deceleration parameter to second order, which we use to characterize the backreaction. We find that the fractional shift in the Hubble parameter with respect to the input background cosmological model is $\overline{\Delta }\approx {10}^{-5}$, which leads to ${\Omega }_{\mathrm{eff}}$ of the order of a few times ${10}^{-5}$. In addition, we find that an appropriate measure of the fractional shift in the deceleration parameter $\overline{Q}$ is very large.

Many models have been studied that contain more than one species of dark matter and some of these couple the cold dark matter (CDM) to a light scalar field. In doing this we introduce additional long range forces, which in turn can significantly affect our estimates of cosmological parameters if not properly accounted for. It is, therefore, important to study these models and their resulting cosmological implications. We present a model in which a fraction of the total cold dark matter density is coupled to a scalar field. We study the background and perturbation evolution and calculate the resulting cosmic microwave background anisotropy spectra. The greater the fraction of dark matter coupled to the scalar field and the stronger the coupling strength, the greater the deviation of the background evolution from $\Lambda \mathrm{CDM}$. Previous work, with a single coupled dark matter species, has found an upper limit on the coupling strength of order $\mathcal{O}(0.1)$. We find that with a coupling of this magnitude more than half the dark matter can be coupled to a scalar field without producing any significant deviations from $\Lambda \mathrm{CDM}$.

Gravitational-wave bursts are observable as bright clusters of pixels in spectrograms of strain power. Clustering algorithms can be used to identify candidate gravitational-wave events. Clusters are often identified by grouping together seed pixels in which the power exceeds some threshold. If the gravitational-wave signal is long-lived, however, the excess power may be spread out over many pixels, none of which are bright enough to become seeds. Without seeds, the problem of detection through clustering becomes more complicated. In this paper, we investigate seedless clustering algorithms in searches for long-lived narrow-band gravitational-wave bursts. Using four astrophysically motivated test waveforms, we compare a seedless clustering algorithm to two algorithms using seeds. We find that the seedless algorithm can detect gravitational-wave signals (at a fixed false-alarm and false-dismissal rate) at distances between $1.5–2\times$ those achieved with the seed-based clustering algorithms, corresponding to significantly increased detection volumes: $4.2–7.4\times$. This improvement in sensitivity may extend the reach of second-generation detectors such as Advanced LIGO and Advanced Virgo deeper into astrophysically interesting distances.

Weakly interacting massive particles (WIMPs) are a theoretical class of particles that are excellent dark matter candidates. WIMP annihilation or decay may produce essentially monochromatic $\gamma$ rays detectable by the Fermi Large Area Telescope (LAT) against the astrophysical $\gamma$-ray emission of the Galaxy. We have searched for spectral lines in the energy range 5–300 GeV using 3.7 years of data, reprocessed with updated instrument calibrations and an improved energy dispersion model compared to the previous Fermi-LAT Collaboration line searches. We searched in five regions selected to optimize sensitivity to different theoretically motivated dark matter density distributions. We did not find any globally significant lines in our a priori search regions and present 95% confidence limits for annihilation cross sections of self-conjugate WIMPs and decay lifetimes. Our most significant fit occurred at 133 GeV in our smallest search region and had a local significance of 3.3 standard deviations, which translates to a global significance of 1.5 standard deviations. We discuss potential systematic effects in this search, and examine the feature at 133 GeV in detail. We find that the use both of reprocessed data and of additional information in the energy dispersion model contributes to the reduction in significance of the linelike feature near 130 GeV relative to significances reported in other works. We also find that the feature is narrower than the LAT energy resolution at the level of 2 to 3 standard deviations, which somewhat disfavors the interpretation of the 133 GeV feature as a real WIMP signal.

We discuss the role of the impact-parameter–dependent quantities. Their use, along with the available experimental data on elastic scattering at the LHC, could serve as an additional insight into the asymptotics.

We analyze the extension of the minimal supersymmetric standard model which includes extra $Y=(0,\pm 1)$ supersymmetric triplets with a global $SU(2{)}_L\otimes SU(2{)}_R$ symmetry spontaneously broken to the custodial $SU(2{)}_V$ by the vacuum expectation value of the neutral scalar components of doublets and triplets. The model is the supersymmetrization of the nonsupersymmetric model introduced long ago by Georgi and Machacek where the $\rho$ parameter is kept to unity at the tree level by the custodial symmetry. Accordingly, the scalar sector is classified into degenerate $SU(2{)}_V$ multiplets: singlets, triplets (including the one containing the Godstone bosons) and fiveplets. The singly and doubly charged chiral superfields play a key role in the unitarization of the theory. The couplings of the standard model-like Higgs to vector bosons (including $\gamma \gamma$) and fermions, and the corresponding Higgs signal strengths, are in agreement with LHC experimental data for a large region of the parameter space. Breaking of custodial invariance by radiative corrections suggests a low-scale mechanism of supersymmetry breaking.

Most of the traditional technicolor-based models are known to be in a strong tension with the electroweak precision tests. We show that this serious issue is naturally cured in strongly coupled sectors with chiral-symmetric vectorlike gauge interactions in the framework of the gauged linear $\sigma$ model. We discuss possible phenomenological implications of such a nonstandard chiral-symmetric technicolor scenario in its simplest formulation preserving the standard model (SM) Higgs mechanism. For this purpose, we assume the existence of an extra technifermion sector confined under extra $SU(3{)}_{\mathrm{TC}}$ at the energy scales reachable at the LHC, ${\Lambda }_{\mathrm{TC}}\sim 0.1–1\mathrm{TeV}$ and interacting with the SM gauge bosons in a chiral-symmetric (vectorlike) way. In the framework of this scenario, the SM Higgs vacuum expectation value acquires a natural interpretation in terms of the condensate of technifermions in confinement in the nearly conformal limit. We study the influence of the lowest-lying composite physical states, namely, technipions, technisigma, and constituent technifermions, on the Higgs sector properties in the SM and other observables at the LHC. We find that the predicted Higgs boson signal strengths in $\gamma \gamma$, vector-boson $V{V}^{*}$, and fermion $f\overline{f}$ decay channels can be sensitive to the new strongly coupled dynamics and are consistent with the current SM-like Higgs boson observations in the limit of relatively small Higgs-technisigma mixing. At the same time, the chiral-symmetric technicolor provides us with rich technipion phenomenology at the LHC, and its major implications are discussed in detail.

We perform a full amplitude analysis of $B^0\to {\psi }^{\prime }{K}^{+}{\pi }^{-}$ decays, with ${\psi }^{\prime }\to {\mu }^{+}{\mu }^{-}$ or $e^{+}{e}^{-}$, to constrain the spin and parity of the $Z(4430{)}^{-}$. The $J^P=1^{+}$ hypothesis is favored over the $0^{-}$, $1^{-}$, $2^{-}$ and $2^{+}$ hypotheses at the levels of $3.4\sigma$, $3.7\sigma$, $4.7\sigma$ and $5.1\sigma$, respectively. The analysis is based on a $711{\mathrm{fb}}^{-1}$ data sample that contains $772\times {10}^6$ $B\overline{B}$ pairs collected at the ${\rm Y}(4S)$ resonance by the Belle detector at the asymmetric-energy $e^{+}{e}^{-}$ collider KEKB.

A variant of variationally optimized perturbation, incorporating renormalization group properties in a straightforward way, uniquely fixes the variational mass interpolation in terms of the anomalous mass dimension. It is used at three successive orders to calculate the nonperturbative ratio $F_{\pi }/\overline{\Lambda }$ of the pion decay constant and the basic QCD scale in the $\overline{MS}$ scheme. We demonstrate the good stability and (empirical) convergence properties of this modified perturbative series for this quantity, and provide simple and generic cures to previous problems of the method, principally the generally nonunique and nonreal optimal solutions beyond lowest order. Using the experimental $F_{\pi }$ input value we determine ${\overline{\Lambda }}^{n_f=2}\simeq {359}_{-25}^{+38}\pm 5\mathrm{MeV}$ and ${\overline{\Lambda }}^{n_f=3}={317}_{-7}^{+14}\pm 13\mathrm{MeV}$, where the first quoted errors are our estimate of theoretical uncertainties of the method, which we consider conservative. The second uncertainties come from the present uncertainties in $F_{\pi }/F$ and $F_{\pi }/F_0$, where $F$ ($F_0$) is $F_{\pi }$ in the exact chiral $SU(2)$ ($SU(3)$) limits. Combining the ${\overline{\Lambda }}^{n_f=3}$ results with a standard perturbative evolution provides a new independent determination of the strong coupling constant at various relevant scales, in particular ${\overline{\alpha }}_S(m_Z)={0.1174}_{-.0005}^{+.0010}\pm 0.001\pm {0.0005}_{\mathrm{evol}}$ and ${\overline{\alpha }}_S^{n_f=3}(m_{\tau })={0.308}_{-.004}^{+.007}\pm 0.007\pm {0.002}_{\mathrm{evol}}$. A less conservative interpretation of our prescriptions favors central values closer to the upper limits of the first uncertainties. The theoretical accuracy is well comparable to the most precise recent single determinations of ${\alpha }_S$, including some very recent lattice simulation determinations with fully dynamical quarks.

We study the production of top-antitop pairs at the Large Hadron Collider as a test bed for discovering heavy $Z^{\prime }$ bosons belonging to a composite Higgs model, as in this scenario, such new gauge interaction states are sizeably coupled to the third-generation quarks of the Standard Model. We study their possible appearance in cross sections, as well as (charge and spin) asymmetry distributions. Our calculations are performed in the minimal four-dimensional formulation of such a scenario, namely the four-dimensional composite Higgs model, which embeds five new $Z^{\prime }$s. We pay particular attention to the case of nearly degenerate resonances, highlighting the conditions under which these are separable in the aforementioned observables. We also discuss the impact of the intrinsic width of the new resonances on the event rates and various distributions. We confirm that the 14 TeV stage of the LHC will enable one to detect two such states, assuming standard detector performance and machine luminosity. A mapping of the discovery potential of the LHC for these new gauge bosons is given. Finally, from the latter, several benchmarks are extracted which are amenable to experimental investigation.