We describe a solution-generating technique that maps a static charged solution of the Einstein-Maxwell theory in four (or five) dimensions to a five-dimensional solution of the Einstein-Maxwell-Dilaton theory. As examples of this technique first we show how to construct the dilatonic version of the Reissner-Nordström solution in five dimensions and then we consider the more general case of the double black hole solutions and describe some of their properties. We found that in the general case the value of the conical singularities in between the black holes is affected by the dilaton’s coupling constant to the gauge field and only in the particular case when all charges are proportional to the masses this dependence cancels out.

The exterior geometry of a neutron star can be approximated by relativistic multipole moments of a parametrized metric using Ernst potential formalism. This spacetime can be tested with electromagnetic wave observation of astrophysical black holes. In the present paper, I simulate x-ray reflection spectra of a thin accretion disk with future x-ray missions. The purpose of this work is to understand whether x-ray reflection spectroscopy can distinguish the neutron star from the Kerr solution of general relativity. I found that for the higher value of spin and multipole moment parameters, there are small differences in the shape of neutron star iron lines. It is hard to distinguish neutron star iron lines from Kerr ones due to the small deviations. Also, electromagnetic wave observation of slow rotating neutron stars is marginally consistent with Kerr black holes of general relativity.

In this paper the deflection angle of light by a rotating Teo wormhole spacetime is calculated in the weak limit approximation. We mainly focus on the weak deflection angle by revealing the gravitational lensing as a partially global topological effect. We apply the Gauss-Bonnet theorem (GBT) to the optical geometry osculating the Teo-Randers wormhole optical geometry to calculate the deflection angle. Furthermore we find the same result using the standard geodesic method. We have found that the deflection angle can be written as a sum of two terms, namely the first term is proportional to the throat of the wormhole and depends entirely on the geometry, while the second term is proportional to the spin angular momentum parameter of the wormhole. A direct observation using lensing can shed light and potentially test the nature of rotating wormholes by comparing with the black holes systems.

We show that a corpuscular description of gravity can lead to an inflationary scenario similar to Starobinsky’s model without requiring the introduction of the inflaton field. All relevant properties are determined by the number of gravitons in the cosmological condensate or, equivalently, by their Compton length. In particular, the relation between the Hubble parameter $H$ and its time derivative $\dot{H}$ required by cosmic microwave background observations at the end of inflation, as well as the (minimum) initial value of the slow-roll parameter, are naturally obtained from the Compton size of the condensate.

In this paper, by considering an absorption probability independent of photon wavelength, we show that current type Ia supernovae (SNe Ia) and gamma-ray burst (GRB) observations plus high-redshift measurements of the cosmic microwave background (CMB) radiation temperature support cosmic acceleration regardless of the transparent-universe assumption. Two flat scenarios are considered in our analyses: the $\mathrm{\Lambda }\mathrm{CDM}$ model and a kinematic model. We consider $\tau (z)=2\ln (1+z{)}^{ϵ}$, where $\tau (z)$ denotes the opacity between an observer at $z=0$ and a source at $z$. This choice is equivalent to deforming the cosmic distance duality relation as $D_L{D}_A^{-1}=(1+z{)}^{2+ϵ}$ and, if the absorption probability is independent of photon wavelength, the CMB temperature evolution law is $T_{\mathrm{CMB}}(z)=T_0(1+z{)}^{1+2ϵ/3}$. By marginalizing on the $ϵ$ parameter, our analyses rule out a decelerating universe at 99.99% C.L. for all scenarios considered. Interestingly, by considering only SNe Ia and GRBs observations, we obtain that a decelerated universe—indicated by ${\mathrm{\Omega }}_{\mathrm{\Lambda }}\le 0.33$ and $q_0>0$—is ruled out around $1.5\sigma$ C.L. and $2\sigma$ C.L., respectively, regardless of the transparent-universe assumption.

Future surveys will access large volumes of space and hence very long wavelength fluctuations of the matter density and gravitational field. It has been argued that the set of secondary effects that affect the galaxy distribution, relativistic in nature, will bring new, complementary cosmological constraints. We study this claim in detail by focusing on a subset of wide-area future surveys: Stage-4 cosmic microwave background experiments and photometric redshift surveys. In particular, we look at the magnification lensing contribution to galaxy clustering and general-relativistic corrections to all observables. We quantify the amount of information encoded in these effects in terms of the tightening of the final cosmological constraints as well as the potential bias in inferred parameters associated with neglecting them. We do so for a wide range of cosmological parameters, covering neutrino masses, standard dark-energy parametrizations and scalar-tensor gravity theories. Our results show that, while the effect of lensing magnification to number counts does not contain a significant amount of information when galaxy clustering is combined with cosmic shear measurements, this contribution does play a significant role in biasing estimates on a host of parameter families if unaccounted for. Since the amplitude of the magnification term is controlled by the slope of the source number counts with apparent magnitude, $s(z)$, we also estimate the accuracy to which this quantity must be known to avoid systematic parameter biases, finding that future surveys will need to determine $s(z)$ to the $\sim 5\%–10\%$ level. On the contrary, large-scale general-relativistic corrections are irrelevant both in terms of information content and parameter bias for most cosmological parameters but significant for the level of primordial non-Gaussianity.

Models that seek to explain cosmic acceleration through modifications to general relativity (GR) evade stringent Solar System constraints through a restoring, screening mechanism. Down-weighting the high-density, screened regions in favor of the low density, unscreened ones offers the potential to enhance the amount of information carried in such modified gravity models. In this work, we assess the performance of a new “marked” transformation and perform a systematic comparison with the clipping and logarithmic transformations, in the context of $\mathrm{\Lambda }\mathrm{CDM}$ and the symmetron and $f(R)$ modified gravity models. Performance is measured in terms of the fractional boost in the Fisher information and the signal-to-noise ratio (SNR) for these models relative to the statistics derived from the standard density distribution. We find that all three statistics provide improved Fisher boosts over the basic density statistics. The model parameters for the marked and clipped transformation that best enhance signals and the Fisher boosts are determined. We also show that the mark is useful both as a Fourier and real-space transformation; a marked correlation function also enhances the SNR relative to the standard correlation function, and can on mildly nonlinear scales show a significant difference between the $\mathrm{\Lambda }\mathrm{CDM}$ and the modified gravity models. Our results demonstrate how a series of simple analytical transformations could dramatically increase the predicted information extracted on deviations from GR, from large-scale surveys, and give the prospect for a much more feasible potential detection.

Percolation analysis has long been used to quantify the connectivity of the cosmic web. Most of the previous work is based on density fields on grids. By smoothing into fields, we lose information about galaxy properties like shape or luminosity. The lack of mathematical modeling also limits our understanding for the percolation analysis. To overcome these difficulties, we have studied percolation analysis based on discrete points. Using a friends-of-friends (FoF) algorithm, we generate the $S-bb$ relation, between the fractional mass of the largest connected group ($S$) and the FoF linking length ($bb$). We propose a new model, the probability cloud cluster expansion theory to relate the $S-bb$ relation with correlation functions. We show that the $S-bb$ relation reflects a combination of all orders of correlation functions. Using N-body simulation, we find that the $S-bb$ relation is robust against redshift distortion and incompleteness in observation. From the Bolshoi simulation, with halo abundance matching (HAM), we have generated a mock galaxy catalog. Good matching of the projected two-point correlation function with observation is confirmed. However, comparing the mock catalog with the latest galaxy catalog from Sloan Digital Sky Survey (SDSS) Data Release (DR)12, we have found significant differences in their $S-bb$ relations. This indicates that the mock galaxy catalog cannot accurately retain higher-order correlation functions than the two-point correlation function, which reveals the limit of the HAM method. As a new measurement, the $S-bb$ relation is applicable to a wide range of data types, fast to compute, and robust against redshift distortion and incompleteness and contains information of all orders of correlation functions.

Homogeneous oscillations of the inflaton after inflation can be unstable to small spatial perturbations even without coupling to other fields. We show that for inflaton potentials $\propto |\varphi {|}^{2n}$ near $|\varphi |=0$ and flatter beyond some $|\varphi |=M$, the inflaton condensate oscillations can lead to self-resonance, followed by its complete fragmentation. We find that for nonquadratic minima ($n>1$), shortly after backreaction, the equation of state parameter, $w\to 1/3$. If $M\ll m_{\mathrm{Pl}}$, radiation domination is established within less than an $e$-fold of expansion after the end of inflation. In this case self-resonance is efficient and the condensate fragments into transient, localised spherical objects which are unstable and decay, leaving behind them a virialized field with mean kinetic and gradient energies much greater than the potential energy. This end-state yields $w=1/3$. When $M\sim m_{\mathrm{Pl}}$ we observe slow and steady, self-resonance that can last many $e$-folds before backreaction eventually shuts it off, followed by fragmentation and $w\to 1/3$. We provide analytical estimates for the duration to $w\to 1/3$ after inflation, which can be used as an upper bound (under certain assumptions) on the duration of the transition between the inflationary and the radiation dominated states of expansion. This upper bound can reduce uncertainties in CMB observables such as the spectral tilt $n_{\mathrm{s}}$, and the tensor-to-scalar ratio $r$. For quadratic minima ($n=1$), $w\to 0$ regardless of the value of $M$. This is because when $M\ll m_{\mathrm{Pl}}$, long-lived oscillons form within an $e$-fold after inflation, and collectively behave as pressureless dust thereafter. For $M\sim m_{\mathrm{Pl}}$, the self-resonance is inefficient and the condensate remains intact (ignoring long-term gravitational clustering) and keeps oscillating about the quadratic minimum, again implying $w=0$.

We perform Monte Carlo simulations of transrelativistic shear acceleration dedicated to a jet-cocoon system of active galactic nuclei. A certain fraction of galactic cosmic rays in a halo is entrained, and sufficiently high-energy particles can be injected to the reacceleration process and further accelerated up to 100 EeV. We show that the shear reacceleration mechanism leads to a hard spectrum of escaping cosmic rays, $d{L}_E/dE\propto E^{-1}-E^0$, distinct from a conventional $E^{-2}$ spectrum. The supersolar abundance of ultrahigh-energy nuclei is achieved due to injections at TeV-PeV energies. As a result, we find that the highest-energy spectrum and mass composition can be reasonably explained by our model without contradictions with the anisotropy data.

Collective neutrino oscillations are induced by the presence of neutrinos themselves. As such, they are intrinsically nonlinear phenomena and are much more complex than linear counterparts such as the vacuum or Mikheyev-Smirnov-Wolfenstein oscillations. They obey integro-differential equations, for which it is also very challenging to obtain numerical solutions. If one focuses on the onset of collective oscillations, on the other hand, the equations can be linearized and the technique of linear analysis can be employed. Unfortunately, however, it is well known that such an analysis, when applied with discretizations of continuous angular distributions, suffers from the appearance of so-called spurious modes: unphysical eigenmodes of the discretized linear equations. In this paper, we analyze in detail the origin of these unphysical modes and present a simple solution to this annoying problem. We find that the spurious modes originate from the artificial production of pole singularities instead of a branch cut on the Riemann surface by the discretizations. The branching point singularities on the Riemann surface for the original nondiscretized equations can be recovered by approximating the angular distributions with polynomials and then performing the integrals analytically. We demonstrate for some examples that this simple prescription does remove the spurious modes. We also propose an even simpler method: a piecewise linear approximation to the angular distribution. It is shown that the same methodology is applicable to the multienergy case as well as to the dispersion relation approach that was proposed very recently.

Standard cosmological models do predict a measurable amount of anisotropies in the intensity and linear polarization of the cosmic microwave background radiation (CMB) via Thomson scattering, even though these theoretical models do not predict circular polarization for CMB radiation. In other hand, the circular polarization of CMB has not been excluded in observational evidences. Here we estimate the circular polarization power spectrum $C_l^{V(S)}$ in CMB radiation due to Compton scattering and nonlinear photon-photon forward scattering via Euler-Heisenberg effective Lagrangian. We have estimated the average value of circular power spectrum is $l(l+1)C_l^{V(S)}/(2\pi )\sim {10}^{-4}(\mu {\mathrm{K})}^2$ for $l\sim 300$ at present time which is smaller than recently reported data for upper limit of circular polarization (SPIDER collaboration). As a result to test our results, the ability to detect nano-Kelvin level signals of CMB circular polarization requires. We also show that the generation of B-mode polarization for CMB photons in the presence of the primordial scalar perturbation via Euler-Heisenberg interaction is possible however this contribution for B-mode polarization is not remarkable.

The cusp burst radiation of superconducting cosmic string (SCS) loops is thought to be a possible origin of observed fast radio bursts with the model-predicted radiation spectrum and the redshift- and energy-dependent event rate, we fit the observational redshift and energy distributions of 21 Parkes fast radio bursts and constrain the model parameters. It is found that the model can basically be consistent with the observations, if the current on the SCS loops has a present value of $\sim {10}^{16}{\mu }_{17}^{9/10}\mathrm{esu}{\mathrm{s}}^{-1}$ and evolves with redshift as an empirical power law $\sim (1+z{)}^{-1.3}$, where ${\mu }_{17}=\mu /{10}^{17}\mathrm{g}{\mathrm{cm}}^{-1}$ is the string tension. This current evolution may provide a clue to probe the evolution of the cosmic magnetic fields and the gathering of the SCS loops to galaxy clusters.

Axial anomaly and nesting is elucidated in the context of the inhomogeneous chiral phase. Using the Gross-Neveu models in $1+1$ dimensions, we shall discuss axial anomaly and nesting from two different points of view: one is inhomogeneous chiral transition and the other is the Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) state in superconductivity, which are closely related to each other by way of duality. It is shown that axial anomaly leads to a particular kind of the FFLO state within the two dimensional Nambu-Jona Lasinio model, where axial anomaly is manifested in a different mode. Nesting is a driving mechanism for both phenomena, but its realization has different features. We reconsider the effect of nesting in the context of duality.

In view of the recent applications of chiral anomaly to various fields beyond particle physics, we discuss some basic aspects of chiral anomaly which may help deepen our understanding of chiral anomaly in particle physics also. It is first shown that Berry’s phase (and its generalization) for the Weyl model $H=v_F\overrightarrow{\sigma }·\overrightarrow{p}(t)$ assumes a monopole form at the exact adiabatic limit but deviates from it off the adiabatic limit and vanishes in the high frequency limit of the Fourier transform of $\overrightarrow{p}(t)$ for bounded $|\overrightarrow{p}(t)|$. An effective action, which is consistent with the nonadiabatic limit of Berry’s phase, combined with the Bjorken-Johnson-Low prescription, gives normal equal-time space-time commutators and no chiral anomaly. In contrast, an effective action with a monopole at the origin of the momentum space, which describes Berry’s phase in the precise adiabatic limit but fails off the adiabatic limit, gives anomalous space-time commutators and a covariant anomaly to the gauge current. We regard this anomaly as an artifact of the postulated monopole and not a consequence of Berry’s phase. As for the recent application of the chiral anomaly to the description of effective Weyl fermions in condensed matter and nuclear physics, which is closely related to the formulation of lattice chiral fermions, we point out that the chiral anomaly for each species doubler separately vanishes for a finite lattice spacing, contrary to the common assumption. Instead, a general form of pair creation associated with the spectral flow for the Dirac sea with finite depth takes place. This view is supported by the Ginsparg-Wilson fermion, which defines a single Weyl fermion without doublers on the lattice and gives a well-defined index (anomaly) even for a finite lattice spacing. A different use of anomaly in analogy to the partially conserved axial-vector current is also mentioned and could lead to an effect without fermion number nonconservation.

We study the prospective sensitivity to $CP$-violating two Higgs doublet models from the 14 TeV LHC and future electric dipole moment (EDM) experiments. We concentrate on the search for a resonant heavy Higgs that decays to a $Z$ boson and a SM-like Higgs $h$, leading to the $Z(\ell \ell )h(b\overline{b})$ final state. The prospective LHC reach is analyzed using the Boosted Decision Tree method. We illustrate the complementarity between the LHC and low energy EDM measurements and study the dependence of the physics reach on the degree of deviation from the alignment limit. In all cases, we find that there exists a large part of parameter space that is sensitive to both EDMs and LHC searches.

Motivated by the measurements of $b\to s{\ell }^{+}{\ell }^{-}$ transitions, including $R(K)$ and $R(K^{*})$, we examine lepton flavor (universality) violation in $B$ decays and its connections to $\mu \to e\gamma$ in generic leptoquark models. Considering all 10 representations of scalar and vector leptoquarks under the Standard Model gauge group we compute the tree-level matching for semileptonic $b$-quark operators as well as their loop effects in $\ell \to {\ell }^{\prime }\gamma$. In our phenomenological analysis, we correlate $R(K)$, $R(K^{*})$ and the other $b\to s{\mu }^{+}{\mu }^{-}$ data to $\mu \to e\gamma$ and $b\to s\mu e$ transitions for the three leptoquark representations that generate left-handed currents in $b\to s{\ell }^{+}{\ell }^{-}$ transitions and, therefore, provide a good fit to data. We find that while new physics contributions to muons are required by the global fit, couplings to electrons can be sizeable without violating the stringent bounds from $\mu \to e\gamma$. In fact, if the effect in electrons in $b\to s{\ell }^{+}{\ell }^{-}$ has the opposite sign from the effect in muons, the bound from $\mu \to e\gamma$ can always be avoided. However, unavoidable effects in $b\to s\mu e$ transitions (i.e. $B_s\to \mu e$, $B\to K\mu e$, etc.) appear that are within the reach of LHCb and BELLE II.

We compute the beta functions for the three gauge couplings and the Yukawa matrices of a general two-Higgs-doublet model in the modified minimal subtraction scheme to three loops. The calculations are performed using Lorenz gauge in the unbroken phase. We discuss in detail the occurrence of poles in anomalous dimensions and propose practical prescriptions to avoid them. We provide explicit results for the often used ${\mathbb{Z}}_2$-symmetric versions of the two-Higgs-doublet model of types I, II, X, and Y. Furthermore, we provide the first independent cross-check of the three-loop Yukawa coupling beta functions of the Standard Model.

The relations between the baryon-baryon elastic scattering phase shifts and the two-particle energy spectrum in the elongated box are established. We studied the cases with both the periodic boundary condition and twisted boundary condition in the center of mass frame. The framework is also extended to the system of nonzero total momentum with periodic boundary condition in the moving frame. Moreover, we discussed the sensitivity functions $\sigma (q)$ that represent the sensitivity of higher scattering phases. Our analytical results will be helpful to extract the baryon-baryon elastic scattering phase shifts in the continuum from lattice QCD data by using elongated boxes.

We present an investigation of the electromagnetic pion form factor, $F_{\pi }(Q^2)$, at small values of the four-momentum transfer $Q^2$ ($\lesssim 0.25{\mathrm{GeV}}^2$), based on the gauge configurations generated by the European Twisted Mass Collaboration with $N_f=2$ twisted-mass quarks at maximal twist including a clover term. Momentum is injected using nonperiodic boundary conditions and the calculations are carried out at a fixed lattice spacing ($a\simeq 0.09\mathrm{fm}$) and with pion masses equal to its physical value, 240 MeV and 340 MeV. Our data are successfully analyzed using chiral perturbation theory at next-to-leading order in the light-quark mass. For each pion mass two different lattice volumes are used to take care of finite size effects. Our final result for the squared charge radius is $⟨r^2{⟩}_{\pi }=0.443(29){\mathrm{fm}}^2$, where the error includes several sources of systematic errors except the uncertainty related to discretization effects. The corresponding value of the SU(2) chiral low-energy constant ${\overline{\ell }}_6$ is equal to ${\overline{\ell }}_6=16.2(1.0)$.