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H. B. Benaoum

Publications and source records attributed to H. B. Benaoum.

At least 19 recordsLinked to original sources

Early dark energy induced by non-linear electrodynamics

In this work, we introduce a parametrization of early dark energy that mimics radiation at early times and governs the present acceleration of the Universe. We show that such parametrization models non-linear electrodynamics in the early Universe and investigate the cosmological viability of the model. In our scenario, the early dark energy is encoded in the non-linearity of the electromagnetic fields through a parameter $β$ that changes the Lagrangian of the system, and the parameters $γ_s$ and $α$, that define the departure from the standard model constant equation of state. We use a Bayesian method and the modular software \textsc{CosmoSIS} to find the best values for the model's free parameters with precomputed likelihoods from Planck 2018, primordial nucleosynthesis data, inferred distances from different wide galaxy surveys and luminosity distances of SNIa from Pantheon and SH0ES, such that $γ_s =$ 0.468 $\pm$ 0.026 and $α=$ -0.947 $\pm$ 0.032, as opposed to $Λ$CDM where $γ_s = β=$ 0 and there is no equivalence for the $α$ parameter. Our results predict an earlier formation of the structure and a shorter age of the Universe compared with the canonical cosmological model. One of the main findings of our work is that this kind of dark energy alleviates the ongoing tensions in cosmology, the Hubble tension and the so-called $σ_8$ tension, which predicted values by our model are H$_o =$ 70.2 $\pm$ 0.9 km/s/Mpc and $σ_8 =$ 0.798 $\pm$ 0.007. The reported values lie between the inferred values inferred from early and late (local) Universe observations. Future observations will shed light on the nature of the dark energy, its impact on the structure formation, and its dynamics.

gr-qc↗

Inflation Driven by Non-Linear Electrodynamics

We investigate the inflation driven by a nonlinear electromagnetic field based on an NLED lagrangian density ${\cal L}_{\text{nled}} = - {F} f \left( {F} \right)$, where $f \left( {F}\right)$ is a general function depending on ${F}$. We first formulate an $f$-NLED cosmological model with a more general function $f \left( {F}\right)$ and show that all NLED models can be expressed in this framework; then, we investigate in detail two interesting examples of the function $f \left( {F}\right)$. We present our phenomenological model based on a new Lagrangian for NLED. Solutions to the field equations with the physical properties of the cosmological parameters are obtained. We show that the early Universe had no Big-Bang singularity, which accelerated in the past. We also investigate the qualitative implications of NLED by studying the inflationary parameters, like the slow-roll parameters, spectral index $n_s$, and tensor-to-scalar ratio $r$, and compare our results with observational data. Detailed phase-space analysis of our NLED cosmological model is performed with and without matter source. As a first approach, we consider the motion of a particle of unit mass in an effective potential. Our systems correspond to fast-slow systems for physical values of the electromagnetic field and the energy densities at the end of inflation. We analyze a complementary system using Hubble-normalized variables to investigate the cosmological evolution before the matter-dominated Universe.

gr-qc↗

$TeV$-Scale Resonant Leptogenesis $A_4$ with a scaling texture

We consider a TeV scale resonant lepogenesis within type-I seesaw mechanism. We show that a concrete model based on $A_4$ flavor symmetry with a scaling ansatz in the neutrino Dirac mass matrix and a retro-circulant heavy Majorana mass matrix can be realized. The full Yukawa coupling matrix $Y_ν$ can be fully reconstructed from the low energy neutrino oscillations data and the quasi-degenerate heavy Majorara neutrino masses. We have carried out a detailed numerical analysis to constrain the Dirac neutrino mass matrix elements. In particular, it was found that its diagonal elements lie near or below the MeV region. Furthermore, we have investigated the allowed regions in the parameter space of the model consistent with both low energy neutrino oscillations data and resonant leptogenesis leading to the observed baryon asymmetry of the universe. Finally, the model has an imperative prediction on the allowed space for the effective Majorana neutrino mass $|m_{ee}|$ in order to account for the observed baryon asymmetry.

hep-ph↗

Matter-antimatter asymmetry induced by non-linear electrodynamics

In this work, we propose an economical model to address some open cosmological problems such as the absence of the initial cosmological singularity, an early acceleration of the Universe and the generation of matter-antimatter asymmetry. The model is based on a scenario in which the early Universe consists of a non-linear electrodynamics fields. It is found that the non-linear electrodynamics model has an equation of state $p=\frac{1}{3} ρ- \frac{4}{3} βρ^{1+α}$ which shows that the Universe undergoes an early epoch acceleration to a radiation era given by $p =\frac{1}{3} ρ$. We show that the singularities in the energy density, pressure and curvature are absent at early stages. In our scenario, the baryon asymmetry is generated by the non-linearity parameter $β$. Additionally, we calculate the resulting baryon asymmetry and discuss how a successful gravitational baryogenesis is obtained for different values of the model's parameter space.

gr-qc↗

Modified Emergent Dark Energy and its Astronomical Constraints

We introduce a modified form of the Phenomenologically Emergent Dark Energy (PEDE) model by showing a very elegant approach. The model is named as Modified Emergent Dark Energy (MEDE) to distinguish from PEDE model and it includes $Λ$CDM, PEDE model, Chevallier-Polarski-Linder model and other cosmological models of interest. We show that the present article offers a very fantastic route to construct other PEDE models in a simple but very elegant way. The model has seven free parameters where the six parameters are the same as in $Λ$CDM or PEDE model and the remaining one parameter `$α$' quantifies the generalization. The present model predicts that dark energy equation of state at present assumes, $w_{\rm DE}\; (z=0) = -1 - \fracα{3 \ln (10)}$ and in the far future (i.e., for $z \longrightarrow -1$), it will evolve asymptotically to $w_{\rm DE} \longrightarrow -1$. We perform a very robust observational analysis of the model using various observational datasets including cosmic microwave background radiation, baryon acoustic oscillations distance measurements, a local value of the Hubble constant and the pantheon sample of Supernovae Type Ia. We find that the $H_0$ tension here is alleviated but not solved, while the only free parameter, $α$ could recover the $Λ$CDM or PEDE for different datasets. In summary, the present article describes a novel route to construct other modified versions of the PEDE model in a very simplified manner.

gr-qc↗

$TeV$-Scale Resonant Leptogenesis with New Scaling Ansatz on Neutrino Dirac Mass Matrix from $A_4$ Flavor Symmetry

We propose a new scaling ansatz in the neutrino Dirac mass matrix to explain the low energy neutrino oscillations data, baryon number asymmetry and neutrinoless double beta decay. In this work, a full reconstruction of the neutrino Dirac mass matrix has been realized from the low energy neutrino oscillations data based on type-I seesaw mechanism. A concrete model based on $A_4$ flavor symmetry has been considered to generate such a neutrino Dirac mass matrix and imposes a relation between the two scaling factors. In this model, the right-handed Heavy Majorana neutrino masses are quasi-degenerate at TeV mass scales. Extensive numerical analysis studies have been carried out to constrain the parameter space of the model from the low energy neutrino oscillations data. It has been found that the parameter space of the Dirac mass matrix elements lies near or below the MeV region and the scaling factor $|κ_1|$ has to be less than 10. Furthermore, we have examined the possibility for simultaneous explanation of both neutrino oscillations data and the observed baryon number asymmetry in the Universe. Such an analysis gives further restrictions on the parameter space of the model, thereby explaining the correct neutrino data as well as the baryon number asymmetry via a resonant leptogenesis scenario. Finally, we show that the allowed space for the effective Majorana neutrino mass $m_{ee}$ is also constrained in order to account for the observed baryon asymmetry.

hep-ph↗

Modified Chaplygin Gas Cosmology with Bulk Viscosity

In this paper, we investigate the viscous modified Chaplygin gas cosmological model. Solutions for different values of the viscosity parameter are obtained using both analytical and numerical methods. We have calculated the deceleration and defined {\em newly} statefinder $\{r, s \}$ pair in D dimensions. It is shown that when $D=4$, the usual statefinder parameters are recovered. Furthermore, we apply the statefinder diagnostic to the MCG model with and without viscosity in $D$ dimensions and explore these parameters graphically.

gr-qc↗

Broken $S_3$ Neutrinos

Motivated by recent measurements which strongly support a nonzero reactor mixing angle $θ_{13}$, we study a deviation from $S_3$ neutrino discrete symmetry by explicitly breaking the neutrino mass matrix with a general retrocirculant matrix. We show that nonzero $θ_{13}$ and nonzero CP violation parameter $J_{CP}$ arise due to the difference between $y_2$ and $y_3$. We demonstrate that it is possible to obtain the experimentally favored results for neutrino masses and mixing angles from this mass matrix. Furthermore, we estimate the effective masses $m_β$ and $m_{ββ}$ and total neutrino mass $\sum |m_i|$ predicted by this mass matrix.

hep-ph↗

Modified Chaplygin Gas Cosmology

Modified Chaplygin gas as an exotic fluid has been introduced in [34]. Essential features of the modified Chaplygin gas as a cosmological model are discussed. Observational constraints on the parameters of the model have been included. The relationship between the modified Chaplygin gas and a homogeneous minimally coupled scalar field are reevaluated by constructing its self-interacting potential. In addition, we study the role of the tachyonic field in the modified Chaplygin gas cosmological model and the mapping between scalar field and tachyonic field is also considered.

gr-qc↗

Non-zero $θ_{13}$ from the Triangular Ansatz and Leptogenesis

Recent experiments indicate a departure from the exact Tri-Bimaximal mixing by measuring definitive non-zero value of $θ_{13}$. Within the framework of type I seesaw mechanism, we reconstruct the triangular Dirac neutrino mass matrix from the $μ-τ$ symmetric mass matrix. The deviation from $μ-τ$ symmetry is then parametrized by adding dimensionless parameters $y_i$ in the triangular mass matrix. In this parametrization of the neutrino mass matrix, the non-zero value $θ_{13}$ is controlled by $Δy = y_4 - y_6$. We also calculate the resulting leptogenesis and show that the triangular texture can generate the observed baryon asymmetry in the universe via leptogenesis scenario.

hep-ph↗

New Parametrization of Neutrino Mixing Matrix

Global fits to neutrino oscillation data are compatible with tri-bimaximal mixing pattern, which predicts $θ_{23} = \fracπ{4}, θ_{12} = \sin^{-1} (\frac{1}{\sqrt{3}})$ and $θ_{13} = 0$. We propose here to parametrize the tri-bimaximal mixing matrix $V_{TBM}$ by its hermitian generator $H_{TBM}$ using the exponential map. Then we use the exponential map to express the deviations from tri-bimaximal pattern by deriving the hermitian matrices $H_{z=0}$ and $H_1$. These deviations might come from the symmetry breaking of the neutrino and charged lepton sectors.

hep-ph↗

h-analogue of Fibonacci Numbers

In this paper, we introduce the h-analogue of Fibonacci numbers for non-commutative h-plane. For h h'= 1 and h = 0, these are just the usual Fibonacci numbers as it should be. We also derive a collection of identities for these numbers. Furthermore, h-Binet's formula for the h-Fibonacci numbers is found and the generating function that generates these numbers is obtained.

math-ph↗

Accelerated Universe from Modified Chaplygin Gas and Tachyonic Fluid

A cosmological model with an exotic fluid is investigated. We show that the equation of state of this ``modified Chaplygin'' gas can describe the current accelerated expansion of the universe. We then reexpress it as FRW cosmological model containing a scalar field $ϕ$ and find its self--interacting potential. Moreover motivated by recent works of Sen [sen1, sen2] and Padmanbhan [pad] on tachyon field theory, a map for this exotic fluid as a normal scalar field $ϕ$ with Lagrangian ${\cal L}_ϕ = \frac{\dotϕ^2}{2} - U (ϕ)$ to the tachyonic field $T$ with Lagrangian ${\cal L}_{T} = - V(T) \sqrt{1 - \dot{T}^2}$ is obtained.

hep-th↗

Perturbative BF-Yang-Mills theory on noncommutative R^4

A U(1) BF-Yang-Mills theory on noncommutative ${\mathbb{R}}^4$ is presented and in this formulation the U(1) Yang-Mills theory on noncommutative ${\mathbb{R}}^4$ is seen as a deformation of the pure BF theory. Quantization using BRST symmetry formalism is discussed and Feynman rules are given. Computations at one-loop order have been performed and their renormalization studied. It is shown that the U(1) BFYM on noncommutative ${\mathbb{R}}^4$ is asymptotically free and its UV-behaviour in the computation of the $β$-function is like the usual SU(N) commutative BFYM and Yang Mills theories.

hep-th↗

More on triangular mass matrices for fermions

A direct proof is given here which shows that instead of 6 complex numbers, the triangular mass matrix for each sector could just be expressed in terms of 5 by performing a specific weak basis transformation, leading therefore to a new textures for triangular mass matrices. Furthermore, starting with the set of 20 real parameters for both sectors, it can shown that 6 redundant parameters can be removed by using the rephasing freedom.

hep-ph↗

Bimaximal mixing from the leptonic new texture for triangular mass matrices

An analysis of the leptonic texture for the new triangular mass matrices has been carried out. In particular, it is shown that both bimaximal and nearly bimaximal solutions for solar and atmospheric neutrino anomalies can be generated within this pattern. We have also derived exact and compact parametrization of the leptonic mixing matrix in terms of the lepton masses and the parameters $α, β'$ and $δ$. A consistency with the CHOOZ reactor result for $V_m{_{13}}$ and a smallness of the Jarlskog's invariant parameter are obtained.

hep-ph↗

(q,h)-analogue of Newton's binomial formula

In this letter, the (q,h)-analogue of Newton's binomial formula is obtained in the (q,h)-deformed quantum plane which reduces for h=0 to the q-analogue. For (q=1,h=0), this is just the usual one as it should be. Moreover, the h-analogue is recovered for q=1. Some properties of the (q,h)-binomial coefficients are also given. This result will contribute to an introduction of the (q,h)-analogue of the well-known functions, (q,h)-special functions and (q,h)-deformed analysis.

math-ph↗