For Gaussian primordial fluctuations the relationship between galaxy and matter overdensities, bias, is most often assumed to be local at the time of observation in the large-scale limit. This hypothesis is however unstable under time evolution, we provide proofs under several (increasingly more realistic) sets of assumptions. In the simplest toy model galaxies are created locally and linearly biased at a single formation time, and subsequently move with the dark matter (no velocity bias) conserving their comoving number density (no merging). We show that, after this formation time, the bias becomes unavoidably nonlocal and nonlinear at large scales. We identify the nonlocal gravitationally induced fields in which the galaxy overdensity can be expanded, showing that they can be constructed out of the invariants of the deformation tensor (Galileons), the main signature of which is a quadrupole field in second-order perturbation theory. In addition, we show that this result persists if we include an arbitrary evolution of the comoving number density of tracers. We then include velocity bias, and show that new contributions appear; these are related to the breaking of Galilean invariance of the bias relation, a dipole field being the signature at second order. We test these predictions by studying the dependence of halo overdensities in cells of fixed dark matter density: measurements in simulations show that departures from the mean bias relation are strongly correlated with the nonlocal gravitationally induced fields identified by our formalism, suggesting that the halo distribution at the present time is indeed more closely related to the mass distribution at an earlier rather than present time. However, the nonlocality seen in the simulations is not fully captured by assuming local bias in Lagrangian space. The effects on nonlocal bias seen in the simulations are most important for the most biased halos, as expected from our predictions. Accounting for these effects when modeling galaxy bias is essential for correctly describing the dependence on triangle shape of the galaxy bispectrum, and hence constraining cosmological parameters and primordial non-Gaussianity. We show that using our formalism we remove an important systematic in the determination of bias parameters from the galaxy bispectrum, particularly for luminous galaxies.

A completely new mechanism to generate the observed amount of large-scale cosmological magnetic fields is introduced in the context of three-form inflation. The amplification of the fields occurs via fourth order dynamics of the vector perturbations and avoids the backreaction problem that plagues most previously introduced mechanisms.

Stable massive neutral particles emitted by astrophysical sources undergo deflection under the gravitational potential of our own Galaxy. The deflection angle depends on the particle velocity and therefore nonrelativistic particles will be deflected more than relativistic ones. If these particles can be detected through neutrino telescopes, cosmic ray detectors or directional dark matter detectors, their arrival directions would appear aligned on the sky along the source-lens direction. On top of this deflection, the arrival direction of nonrelativistic particles is displaced with respect to the relativistic counterpart also due to the relative motion of the source with respect to the observer; this induces an alignment of detections along the sky projection of the source trajectory. The final alignment will be given by a combination of the directions induced by lensing and source proper motion. We derive the deflection-velocity relation for the Milky Way halo and suggest that searching for alignments on detection maps of particle telescopes could be a way to find new particles or new astrophysical phenomena.

We study the four-body ${\tau }^{\pm }\to {\nu }_{\tau }{l}^{\pm }{l}^{\pm }{X}^{\mp }$ decays where $l=e$ or $\mu$ and $X=\pi$, $K$, $\rho$, and $K^{*}$ mesons. These decay processes violate the total lepton number ($|\Delta L|=2$) and can be induced by the exchange of Majorana neutrinos. We consider a scenario where these decays are dominated by the exchange of only one heavy neutrino, which produces an enhancement of the decay amplitude via the resonant mechanism. Searches for these novel decay channels with branching fractions sensitivities of $O({10}^{-7})$ can provide constraints on the parameter space of the Majorana neutrinos, which are stronger than the ones obtained from $\Delta L=2$ decays of charged pseudoscalar mesons.

We study the dynamics of nonequilibrium instabilities in anisotropically expanding systems. The most prominent example of such a system is the “glasma” in the context of relativistic heavy-ion collision experiments, where the expansion is a consequence of approximately boost-invariant initial conditions. Here we consider the problem of parametric resonance in scalar $N$-component quantum field theories with boost-invariant initial conditions, which is similar in spirit. We find that many aspects of the dynamics can be treated analytically by introducing a generalized conformal time. Primary instabilities, which are described by the linearized evolution equations, are seen to lead to a secondary regime of amplifications with strongly enhanced growth rates due to nonlinear corrections. For the secondary instabilities we present a power-counting scheme for weak coupling, and discuss their role for the question of isotropization and the establishment of an equation of state.

In this work we study the renormalization of the electrodynamics of spin $1/2$ fermions in the Poincaré projector formalism which is second order in the derivatives of the fields. We analyze the superficial degree of divergence of the vertex functions of this theory, and calculate at one-loop level the vacuum polarization, fermion self-energy, and $\gamma$-fermion-fermion vertex function, and the divergent piece of the one-loop contributions to the $\gamma$-$\gamma$-fermion-fermion vertex function. It is shown that these functions are renormalizable independently of the value of the gyromagnetic factor $g$, which is a free parameter of the theory. We find a photon propagator and a running coupling constant $\alpha (q^2)$ that depend on the value of $g$. The magnetic moment form factor contains a divergence associated with $g$, which disappears for $g=2$ but, in general, requires the coupling $g$ to be renormalized. A suitable choice of the renormalization condition for the magnetic form factor yields the one-loop finite correction $\Delta g=g\alpha /2\pi$. For a particle with $g=2$ we recover results of Dirac theory for the photon propagator, the running of $\alpha (q^2)$, and the one-loop corrections to the gyromagnetic factor.

Recent results from Higgs boson and supersymmetry searches at the Large Hadron Collider provide strong new motivations for supersymmetric theories with heavy superpartners. We reconsider focus point supersymmetry (FP SUSY), in which all squarks and sleptons may have multi-TeV masses without introducing fine-tuning in the weak scale with respect to variations in the fundamental SUSY-breaking parameters. We examine both FP SUSY and its familiar special case, the FP region of minimal supergravity, also known as the constrained minimal supersymmetric standard model (mSUGRA/CMSSM), and show that they are beautifully consistent with all particle, astroparticle, and cosmological data, including Higgs boson mass limits, null results from SUSY searches, electric dipole moments, $b\to s\gamma$, $B_s\to {\mu }^{+}{\mu }^{-}$, the thermal relic density of neutralinos, and dark matter searches. The observed deviation of the muon’s anomalous magnetic moment from its standard model value may also be explained in FP SUSY, although not in the FP region of mSUGRA/CMSSM. In light of recent data, we advocate refined searches for FP SUSY and related scenarios with heavy squarks and sleptons, and we present a simplified parameter space within mSUGRA/CMSSM to aid such analyses.

We study a minimal flavor-violating extension of the minimal supersymmetric standard model, where higher-dimensional operators in the Kähler potential induce tree-level nonholomorphic Higgs couplings that are controlled by the scale of the physics beyond the minimal supersymmetric standard model and analyze their possible impact on $CP$ violation in $B_s$ and $B_d$ mixing. We consider results on the time-dependent $CP$ asymmetries in $B_s\to \psi \varphi$ and $B_s\to \psi f_0$ from LHCb, in $B_s\to \psi \varphi$ from CDF and D0 and in $B\to \psi K_S$ from the $B$ factories as well as the measurement of an anomalous like-sign dimuon charge asymmetry at D0. Taking into account the stringent bounds on the branching ratio of the rare $B_s\to {\mu }^{+}{\mu }^{-}$ decay, we investigate to which extent the framework allows to address the observed $(2–3)\sigma$ discrepancies in fits of the unitarity triangle. We find that a nonstandard $B_d$ mixing phase, that is in agreement with the current bounds on $CP$ violation in $B_s$ mixing, requires the presence of higher-dimensional operators both in the Kähler potential and the superpotential. The corresponding region of parameter space is characterized by small $\tan \beta \sim 5$, a light Higgs spectrum with masses below $\lesssim 400\mathrm{GeV}$ and will be probed by future measurements at LHCb.

We investigate the possibility to discover the charged Higgs via $pp\to W^{\pm }{H}^{\mp }\to l+{\mathrm{E̸}}_T+b\overline{b}jj$ process at the LHC, which suffers from large QCD backgrounds. We optimize the kinematic cuts to suppress the backgrounds, so that the reconstruction of the charged Higgs through hadronic decay is possible. The angular distribution of the $b$ jet from $H^{\pm }$ decay is investigated as a way to identify the charged scalar from vector bosons.

A new method of employing an isospin chemical potential for QCD-like theories with different number of colors, number of fermion flavors, and in different fermion representations is proposed. The isospin chemical potential, which can be simulated on the lattice due to its positive definite determinant gives a means to probe both confining theories and IR conformal theories without adjusting the lattice spacing and size. As the quark mass is reduced, the isospin chemical potential provides an avenue to extract the chiral condensate in confining theories through the resulting pseudoscalar condensate. For IR conformal theories, the mass anomalous dimension can be extracted in the conformal window through “finite density” scaling since the isospin chemical potential is coupled to a conserved current. In both of these approaches, the isospin chemical potential can be continuously varied for each ensemble at comparable costs while maintaining the hierarchy between the lattice size and lattice spacing. In addition to exploring these methods, finite volume and lattice spacing effects are investigated.

A new model of radiative neutrino masses generated via two-loop diagrams is proposed involving a charge $2/3$ vectorlike quark and a doublet of leptoquark scalars. This model predicts one of the neutrinos to be massless and admits both the normal and inverted neutrino mass hierarchies with correlated predictions for ${\ell }_i\to {\ell }_j+\gamma$ branching ratios. New contributions to CP violation in $B_s^0-{\overline{B}}_s^0$ mixing arise in the model through leptoquark box diagrams, which can explain the anomalous di-muon events reported by the D0 collaboration. These leptoquarks, with masses below 500 GeV, also provide a natural resolution to the apparent discrepancy in the measured values of the CP-violation parameters $\sin 2\beta$ and ${ϵ}_K$.

Precision measurements of nature’s fundamental couplings and a first measurement of the cosmological redshift drift are two of the key targets for future high-resolution ultrastable spectrographs such as CODEX. Being able to do both gives CODEX a unique advantage, allowing it to probe dynamical dark energy models (by measuring the behavior of their equation of state) deep in the matter era and thereby testing classes of models that would otherwise be difficult to distinguish from the standard lambda-cold dark matter paradigm. We illustrate this point with two simple case studies.

Multisoliton form factors in sine-Gordon theory from the bootstrap are compared to finite-volume matrix elements computed using the truncated conformal space approach. We find convincing agreement, and resolve most of the issues raised in a previous work.

We consider entanglement entropy between regions of space in lattice gauge theory. The Hilbert space corresponding to a region of space includes “edge states” that transform nontrivially under gauge transformations. By decomposing the edge states in irreducible representations of the gauge group, the entropy of an arbitrary state is expressed as the sum of three positive terms: a term associated with the classical Shannon entropy of the distribution of boundary representations, a term that appears only for non-Abelian gauge theories and depends on the dimension of the boundary representations, and a term representing nonlocal correlations. The first two terms are the entropy of the edge states, and depend only on observables measurable at the boundary. These results are applied to several examples of lattice gauge theory states, including the ground state in the strong coupling expansion of Kogut and Susskind. In all these examples we find that the entropy of the edge states is the dominant contribution to the entanglement entropy.

There is a widespread belief that the classical small inhomogeneities which gave rise to all structures in the Universe through gravitational instability originated from primordial quantum cosmological fluctuations. However, this transition from quantum to classical fluctuations is plagued with important conceptual issues, most of them related to the application of standard quantum theory to the Universe as a whole. In this paper, we show how these issues can easily be overcome in the framework of the de Broglie–Bohm quantum theory. This theory is an alternative to standard quantum theory that provides an objective description of physical reality, where rather ambiguous notions of measurement or observer play no fundamental role, and which can hence be applied to the Universe as a whole. In addition, it allows for a simple and unambiguous characterization of the classical limit.

We investigate the stability of the Einstein static universe as a nonlocally rotationally symmetric Bianchi type IX solution of the Einstein equations in the presence of both nontilted and tilted fluids. We find that the static universe is unstable to homogeneous perturbations of Bianchi type IX to the future and the past.

We study the scale dependence of halo bias in generic (nonlocal) primordial non-Gaussian (PNG) initial conditions of the type motivated by inflation, parametrized by an arbitrary quadratic kernel. We first show how to generate nonlocal PNG initial conditions with minimal overhead compared to local PNG models for a general class of primordial bispectra that can be written as linear combinations of separable templates. We run cosmological simulations for the local, and nonlocal equilateral and orthogonal models and present results on the scale dependence of halo bias. We also derive a general formula for the Fourier-space bias using the peak-background split in the context of the excursion-set approach to halos and discuss the difference and similarities with the known corresponding result from local bias models. Our peak-background split bias formula generalizes previous results in the literature to include non-Markovian effects and nonuniversality of the mass function and are in better agreement with measurements in numerical simulations than previous results for a variety of halo masses, redshifts and halo definitions. We also derive for the first time quadratic bias results for arbitrary nonlocal PNG, and show that nonlinear bias loops give small corrections at large scales. The resulting well-behaved perturbation theory paves the way to constrain nonlocal PNG from measurements of the power spectrum and bispectrum in galaxy redshift surveys.

We discuss a holographic soft-wall model developed for the description of mesons and baryons with adjustable quantum numbers $n$, $J$, $L$, $S$. This approach is based on an action which describes hadrons with broken conformal invariance and which incorporates confinement through the presence of a background dilaton field. We show that in the case of the bound-state problem (hadronic mass spectrum) two versions of the model with a positive and negative dilaton profile are equivalent to each other by a special transformation of the bulk field. We also comment on recent works which discuss the dilaton sign in the context of soft-wall approaches.

The nonet meson properties are studied in the Nambu-Jona-Lasinio model at finite temperature and chemical potential using dimensional regularization. This study leads to the reasonable description which is mainly similar to one obtained in the model with the cutoff regularization. However, remarkable differences between the two regularizations are observed in the behavior of the chiral phase transition at finite chemical potential.