The standard ΛCDM model of cosmology is formulated as a simple modified gravity coupled to a single scalar field (“darkon”) possessing a nontrivial hidden nonlinear Noether symmetry. The main ingredient in the construction is the use of the formalism of non-Riemannian spacetime volume-elements. The associated Noether conserved current produces stress–energy tensor consisting of two additive parts —

We explore the Lagrangian equation in the background of generalized uncertainty principle. The tunneling radiation through the black ring horizon is observed. We investigated the tunneling radiation through the Hamilton–Jacobi method for solutions of Einstein–Maxwell-dilation gravity theory. The radiation of black ring without back reaction and self-interaction of particles are studied. Furthermore

We study an SO(1,3) pure connection formulation in four dimensions for real-valued fields, inspired by the Capovilla, Dell and Jacobson complex self-dual approach. By considering the CMPR BF action, also, taking into account a more general class of the Cartan–Killing form for the Lie algebra 𝔰𝔬(1,3) and by refining the structure of the Lagrange multipliers, we integrate out the metric variables in

In this work, we present a few simple cosmological models under the modified theory of gravity in the particular form of f(R,𝒯)=R+2f(𝒯), where R is the Ricci Scalar and 𝒯 is the trace of the energy–momentum tensor. Two special cosmological models are studied with (i) hyperbolic scale factor and (ii) specific form of the Hubble parameter. The models are observed to predict relevant cosmological parameters

In this paper, the effect of time is explored on the dynamics of neutral and charged particles around the Schwarzschild (Sch) black hole (BH) environed by quintessence. We introduce a general time conformal factor e𝜖g(t) to the quintessential Sch spacetime, where g(t) is a time (t)-dependent function and 𝜖, a small parameter, that causes perturbation in the corresponding spacetime. The Noether symmetry

We review the main recent progresses in noncommutative space–time phenomenology in underground experiments. A popular model of noncommutative space–time is 𝜃-Poincaré model, based on the Groenewold–Moyal plane algebra. This model predicts a violation of the spin-statistic theorem, in turn implying an energy and angular dependent violation of the Pauli exclusion principle. Pauli exclusion principle

Motivated by the recent interest in underground experiments phenomenology (see Refs. 1–3), we review the main aspects of one specific noncommutative space–time model, based on the Groenewold–Moyal plane algebra, the 𝜃-Poincaré space–time. In the 𝜃-Poincaré scenario, the Lorentz co-algebra is deformed introducing a noncommutativity of space–time coordinates. In such a theory, a new quantum field theory

Deep inelastic scattering is one of the best place to study hadron structures. In this paper we consider the target fragmentation region deep inelastic scattering process at leading twist. The calculations are carried out by applying the collinear expansion. In the collinear expansion formalism the multiple gluon scattering is taken into account and gauge links are obtained systematically and automatically

Cassini mapping of Saturn’s mid‐sized icy moons of well‐preserved complex craters in the 45–95 km size range provides insight into cratering processes at lower surface gravity and on icy targets. These craters are characterized by steep rim scarps, rugged hummocky floor deposits of curvilinear ridges and scarps, and rugged conical central peaks. Ponded impact melt or related deposits are not observed

Quartz and cristobalite ballen aggregates surrounded by dendritic cristobalite in gneiss clasts of impact melt rocks from the Ries impact structure are analyzed by Raman spectroscopy, microscopy, and electron backscattered diffraction to elucidate the development of the characteristic polycrystalline ballen that are defined by curved interfaces between each other. We suggest that the investigated ballen

We report the discovery of a unique, refractory phase‐bearing micrometeorite (WF1202A‐001) from the Sør Rondane Mountains, East Antarctica. A silicate‐rich cosmic spherule (~400 µm) displays a microporphyritic texture containing Ca‐Al‐rich inclusion (CAI)‐derived material (~5–10 area%), including high‐Mg forsterite (Fo98‐99) and enstatite (En98‐99, Wo0‐1). The micrometeorite also hosts a spherical

Lunar mare basalts represent flood volcanism between ~4.0 and 1.2 Ga, therefore, providing insights into the thermal and volcanic history of the Moon. The present study investigates the spectral and chemical characteristics as well as ages of the nearside mare basaltic units from the Grimaldi basin, namely Mare Grimaldi and Mare Riccioli, using a wealth of orbital remote sensing data. This study delineated

The alkali element K is moderately volatile and fluid mobile; thus, it can be influenced by both primary processes (evaporation and recondensation) in the solar nebula and secondary processes (thermal and aqueous alteration) in the parent body. Since these primary and secondary processes would induce different isotopic fractionations, K isotopes could become a potential tracer to distinguish them.

The Didim meteorite contains multiple lithologies and clasts of different petrologic types in a single stone. A mixture of H5 clasts in an unequilibrated H3 host was previously observed in Didim, according to the initial characterization reported in the Meteoritical Bulletin Database, providing an opportunity to investigate molecular composition that contains varying degree of equilibrium with varying

We review on further new developments of Generalized Uncertainty Principle (GUP) and implications for the cosmological vacuum energy. First, we introduce basic aspects of GUP as well as several possible different and viable formulation of it. Second, we move on discussing two recent new types of higher D-dimensional nonperturbative GUP models; which we dub D-Type-I and D-Type-II GUPs. The D-Type-I

The framework of the relativistic quantum mechanics on spatially flat FLRW space–times is considered for deriving the analytical solutions of the Dirac equation in different local charts of these manifolds. Systems of commuting conserved operators are used for determining the fundamental solutions as common eigenspinors giving thus physical meaning to the integration constants related to the eigenvalues

In a previous paper, hereafter referred to as I, we have analyzed the 7 TeV LHC data on W+jets events from the standpoint of IR-improved DGLAP parton shower effects, using the IR-improved Herwiri1.031 parton shower MC in comparison with the Herwig6.5 parton shower MC in the context of the exact O(αs) matrix element matched parton shower framework provided by [email protected] In this paper, we extend

Grand unification groups (GUTs) are constructed from SO(32) heterotic string via Z12−I orbifold compactification. So far, most phenomenological studies from string compactification relied on E8×E8′ heterotic string, and this invites the SO(32) heterotic string very useful for future phenomenological studies. Here, spontaneous symmetry breaking is achieved by Higgsing of the antisymmetric tensor representations

We present the result for the third and fourth moments of the nonsinglet four-loop anomalous dimension of Wilson twist-2 operators in QCD with full color and flavor structures. We also give general expressions for some contributions to the full four-loop anomalous dimension obtained by means of the method, based on LLL-algorithm, which was proposed by us earlier for the reconstruction of a general

Many works, aiming to explain the origin of dark matter or dark energy, consider the existence of hidden (brane)worlds parallel to our own visible world — our usual Universe — in a multidimensional bulk. Hidden braneworlds allow for hidden copies of the Standard Model. For instance, atoms hidden in a hidden brane could exist as dark matter candidates. As a way to constrain such hypotheses, the possibility

The relation between certain Hamiltonians, known as dual, or partner Hamiltonians, under the transformation x→x̄ᾱ has long been used as a method of simplifying spectral problems in quantum mechanics. This paper seeks to examine this further by expressing such Hamiltonians in terms of the generators of sl(2) algebra, which provides another method of solving spectral problems. It appears that doing

Dark matter comprised of axion-like particles (ALPs) generated by the realignment mechanism in the post-inflationary scenario leads to primordial isocurvature fluctuations. The power spectrum of these fluctuations is flat for small wave numbers, extending to scales accessible with cosmological surveys. We use the latest measurements of Cosmic Microwave Background (CMB) primary anisotropies (temperature

Shift-symmetric Horndeski theories admit an interesting class of Schwarzschild black hole solutions exhibiting time-dependent scalar hair. By making use of Lemaître coordinates, we analyze perturbations around these types of black holes, and demonstrate that scalar perturbations around black hole backgrounds inevitably suffer from instabilities. Specifically, we demonstrate the existence of a tachyonic

We adopt the Pearson cross-correlation measure to analyze the LIGO Hanford and LIGO Livingston detector data streams around the events GW150914, GW151012, GW151226 and GW170104. We find that the Pearson cross-correlation method is sensitive to these signals, with correlations peaking when the black hole binaries reconstructed by the LIGO Scientific and Virgo Collaborations, are merging. We compare

Gravitational lensing offers a competitive method to measure H 0 with the goal of 1% precision. A major obstacle comes in the form of lensing degeneracies, such as the mass sheet degeneracy (MSD), which make it possible for a family of density profiles to reproduce the same lensing observables but return different values of H 0 . The modeling process artificially selects one choice from this family

A violation of the distance-duality relation is directly linked with a temporal variation of the electromagnetic fine-structure constant. We consider a number of well-studied f ( T ) gravity models and we revise the theoretical prediction of their corresponding induced violation of the distance-duality relationship. We further extract constraints on the involved model parameters through fine-structure

Recent analyses of the Planck data and quasars at high redshifts have suggested possible deviations from the flat Λ cold dark matter model (ΛCDM), where Λ is the cosmological constant. Here we use machine learning methods to investigate any possible deviations from ΛCDM at both low and high redshifts by using the latest cosmological data. Specifically, we apply the Genetic Algorithms to explore the

The detection of gravitational waves (GWs) propagating through cosmic structures can provide invaluable information on the geometry and content of our Universe as well as on the fundamental theory of gravity. In order to test possible departures from General Relativity, it is essential to analyze, in a modified gravity setting, how GWs propagate through a perturbed cosmological space-time. Working

We consider a model of inflation consisting a triplet of U(1) vector fields with the parity violating interaction which is non-minimally coupled to inflaton. The vector field sector enjoys global O (3) symmetry which admits isotropic configuration and provides not only vector modes but also scalar and tensor modes. We decompose the scalar perturbations into the adiabatic, entropy and isocurvature perturbations

We discuss the effect of clustering for the determination of the merger rate of binary black holes in the LIGO/Virgo mass range. While for a Poissonian initial distribution, and assuming isolated binaries, the allowed fraction of Primordial Black Holes (PBHs) to dark matter (DM) is a few percent, we show that this bound can be relaxed if PBHs are clustered. More precisely we show that for large clustering

Reheating is a process where the energy density of a dominant component of the universe other than radiation, such as a matter component, is transferred into radiation. It is usually assumed that the temperature of the universe decreases due to cosmic expansion even during the reheating process, in which case the maximal temperature of the universe is much higher than the reheat temperature. We point

We consider the nonlinear classical field theory which results from adding to the Maxwell’s Lagrangian the contributions from the weak-field Euler–Heisenberg Lagrangian and a nonuniform part which involves derivatives of the electric and magnetic fields. We focus on the electrostatic case where the magnetic field is set to zero, and we derive the modified Gauss law, resulting in a higher-order differential

In the framework of finite-dimensional Fock space models, for a predefined fixed mean number of particles n̄k, it is shown that there is a “large” multidimensional subspace sn̄k of initial pure states, in the space S of all pure states, unitarily evolving to a subspace Sn̄k of final pure states which yield n̄k. As an example, in particular it follows that the blackbody form of the mean number of particles

A class of effective field theory called delta-theory, which improves ultraviolet divergences in quantum field theory, is considered. We focus on a scalar model with a quartic self-interaction term and construct the delta theory by applying the so-called delta prescription. We quantize the theory using field variables that diagonalize the Lagrangian, which include a standard scalar field and a ghost

Here we propose the extended modified gravity theory named f(R,G,𝒯) gravity where R is the Ricci scalar, G is the Gauss–Bonnet invariant, and 𝒯 is the trace of the stress-energy tensor. We derive the gravitational field equations in f(R,G,𝒯) gravity by taking the least action principle. Next we construct the f(R,G,𝒯) in terms of R, G and 𝒯 in de Sitter as well as power-law expansion. We also construct

We discuss nonminimally coupled cosmologies involving different geometric invariants. Specifically, actions containing a nonminimally coupled scalar field to gravity described, in turn, by curvature, torsion and Gauss–Bonnet scalars are considered. We show that couplings, potentials and kinetic terms are determined by the existence of Noether symmetries which, moreover, allows to reduce and solve dynamics

The recent measurements of the Hubble constant based on the standard ΛCDM cosmology reveal an underlying disagreement between the early-Universe estimates and the late-time measurements. Moreover, as these measurements improve, the discrepancy not only persists but becomes even more significant and harder to ignore. The present situation places the standard cosmology in jeopardy and provides a tantalizing

We study the ability of perturbative models with effective field theory contributions and infra-red resummation to model the redshift space clustering of biased tracers in models where the linear power spectrum has "features"—either imprinted during inflation or induced by non-standard expansion histories. We show that both Eulerian and Lagrangian perturbation theory are capable of reproducing the

So far, the observed effects of dark matter are compatible with it having purely gravitational interactions. However, in many models, dark matter has additional interactions with itself, with the Standard Model, and/or with additional hidden sector states. In this paper, we discuss models in which dark matter interacts through a light vector mediator, giving rise to a long-ranged force between dark

XENONnT is a dark matter direct detection experiment, utilizing 5.9 t of instrumented liquid xenon, located at the INFN Laboratori Nazionali del Gran Sasso. In this work, we predict the experimental background and project the sensitivity of XENONnT to the detection of weakly interacting massive particles (WIMPs). The expected average differential background rate in the energy region of interest, corresponding

The low-energy electronic recoil spectrum in XENON1T provides an intriguing hint for potential new physics. At the same time, observations of horizontal branch stars favor the existence of a small amount of extra cooling compared to the one expected from the Standard Model particle content. In this note, we argue that a hidden photon with a mass of ~ 2.5 keV and a kinetic mixing of ~ 10 −15 allows

Current and future Cosmic Microwave Background (CMB) Radiation experiments are targeting the polarized B -mode signal. The small amplitude of this signal makes a successful measurement challenging for current technologies. Therefore, very accurate studies to mitigate and control possible systematic effects are vital to achieve a successful observation. An additional challenge is coming from the presence

The precise observations of Galactic cosmic ray fluxes of the secondary family, such as Li, Be, B, are expected to have significant implications on our understanding of the cosmic ray origin and propagation. Here we employ the recent very precise measurements of those species by the Alpha Magnetic Spectrometer on the International Space Station, together with their parent species (C and O), as well

Primordial black holes might comprise a significant fraction of the dark matter in the Universe and be responsible for the gravitational wave signals from black hole mergers observed by the LIGO/Virgo collaboration. The spatial clustering of primordial black holes might affect their merger rates and have a significant impact on the constraints on their masses and abundances. We provide some analytical

We study whether binary black hole template banks can be used to search for the gravitational waves emitted by general binary coalescences. To recover binary signals from noisy data, matched-filtering techniques are typically required. This is especially true for low-mass systems, with total massM ##IMG## [https://ej.iop.org/icons/Entities/lesssim.gif] {lesssim} 10 M ⊙ , which can inspiral in the LIGO

For a scalar field ##IMG## [https://ej.iop.org/icons/Entities/phi.gif] {phi} coupled to cold dark matter (CDM), we provide a general framework for studying the background and perturbation dynamics on the isotropic cosmological background. The dark energy sector is described by a Horndeski Lagrangian with the speed of gravitational waves equivalent to that of light, whereas CDM is dealt as a perfect

Here, we discuss the merits of non‐destructive UV laser‐induced fluorescence spectroscopy (LIF) as a flight or laboratory instrument to analyze organic and mineral material in samples on or returned from carbon‐rich asteroids such as (101955) Bennu by NASA’s OSIRIS‐REx mission. LIF is a unique instrument that is non‐destructive while acquiring data, and allows for no sample preparation, crushing, or

The wavelength dependence and temporal evolution of the hypervelocity impact self‐luminous plume (or “flash”) from CO2 ice, water ice, and frozen Martian and lunar regolith simulant targets have been investigated using the Kent two‐stage light‐gas gun. An array of 10 band‐pass filtered photodiodes and a digital camera monitored changes in the impact flash intensity during the different phases of the

We report microscopic, cathodoluminescence, chemical, and O isotopic measurements of FeO‐poor isolated olivine grains (IOG) in the carbonaceous chondrites Allende (CV3), Northwest Africa 5958 (C2‐ung), Northwest Africa 11086 (CM2‐an), and Allan Hills 77307 (CO3.0). The general petrographic, chemical, and isotopic similarity with bona fide type I chondrules confirms that the IOG derived from them. The

In the primordial universe, oscillations of heavy fields can be considered as standard clocks to measure the expansion or contraction history of the universe. Those standard clocks provide a model-independent way of distinguishing inflation and alternative scenarios. However, the mass of the heavy fields may not be a constant mass, but rather mass induced by non-minimal coupling to the Ricci scalar

The recent electron recoil excess observed by XENON1T has a possible interpretation in terms of solar axions coupled to electrons. If such axions are still relativistic at recombination they would also leave a cosmic imprint in the form of an additional radiation component, parameterized by an effective neutrino numberΔ N eff . We explore minimal scenarios with a detectable signal in future CMB surveys:

We investigate whether the 4.4σ tension on H 0 between SH 0 ES 2019 and Planck 2018 can be alleviated by a variation of Newton's constant G N between the early and the late Universe. This changes the expansion rate before recombination, similarly to the addition ofΔ N eff extra relativistic degrees of freedom. We implement a varying G N in a scalar-tensor theory of gravity, with a non-minimal coupling

We will use Fisher information to properly analyze the quantum weak equivalence principle. We argue that gravitational waves will be partially reflected by superconductors. This will occur as the violation of the weak equivalence principle in Cooper pairs is larger than the surrounding ionic lattice. Such reflections of virtual gravitational waves by superconductors can produce a gravitational Casimir

The turbulence in incompressible fluid is represented as a field theory in 3 dimensions. There is no time involved, so this is intended to describe stationary limit of the Hopf functional. The basic fields are Clebsch variables defined modulo gauge transformations (symplectomorphisms). Explicit formulas for gauge invariant Clebsch measure in space of generalized Beltrami flow compatible with steady

The inert Zee model is an extension of the Zee model for neutrino masses. This new model explains the dark matter relic abundance, generates a one-loop neutrino masses and forbids tree-level Higgs-mediated flavor changing neutral currents. Although the dark matter phenomenology of the model is similar to that of the inert doublet model, the presence of new vector-like fermions opens the lepton portal

In this paper, we construct super fuzzy Dirac and chirality operators on the super fuzzy Euclidean hyperboloid EAdSF(2|2) in-instanton and no-instanton sectors. Using the super pseudo-projectors of the noncompact first Hopf fibration, we construct the Ginsparg–Wilson algebra in instanton and no-instanton sectors. Then, using the generators of this algebra, we construct pseudo super-Dirac and chirality

We solve an eigenvalue equation that appears in several papers about a wide range of physical problems. The Frobenius method leads to a three-term recurrence relation for the coefficients of the power series that, under suitable truncation, yields exact analytical eigenvalues and eigenfunctions for particular values of a model parameter. From these solutions some researchers have derived a variety

We show that a Reissner–Nordström (RN) black hole can be formed by dropping a charged thin dust shell onto a RN naked singularity. This is in contrast to the fact that a RN naked singularity is prohibited from forming by dropping a charged thin dust shell onto a RN black hole. This implies the strong tendency of the RN singularity to be covered by a horizon in favor of cosmic censorship. We show that

Creation of charged massless fermion pair by a photon in a constant uniform magnetic field is considered in the one-loop approximation of the (2+1)-dimensional quantum electrodynamics (QED2+1). We calculate the elastic scattering amplitude (EAS) of photon using the polarization operator of photon in the above magnetic field obtained earlier in our work. We analyze the elastic scattering amplitude of

A Satellite Fermi GBM detected recent putative short Gamma Ray Bursts (GRBs) in coincident with the gravitational wave signal GW 150914 produced by the merger of binary black hole (BH). If at least one BH possess magnetic monopole charge in the binary BH system then the short-duration GRBs may produce during the final phase of a binary BH merger. The detection of gravitational waves GW 150914, GW 151226