Anisotropic constant-roll inflation for the Dirac–Born–Infeld model

In this paper, we study a non-canonical extension of a supergravity-motivated model acting as a vivid counterexample to the cosmic no-hair conjecture due to its unusual coupling between scalar and electromagnetic fields. In particular, a canonical scalar field is replaced by the string-inspired Dirac–Born–Infeld one in this extension. As a result, exact anisotropic inflationary solutions for this Dirac–Born–Infeld model are figured out under a constant-roll condition. Furthermore, numerical calculations are performed to verify that these anisotropic constant-roll solutions are indeed attractive during their inflationary phase.

The Physical Properties of ThCr2Si2- Type Co-based Compound SrCo2Si2: An ab-initio Study

In this article, we have studied the mechanical, electronic, and optical features of ThCr2Si2- type compound SrCo2Si2. The investigation has been done by using the first-principles method depend on the density functional theory (DFT) and the calculations were completed with the Cambridge Serial Total Energy Package (CASTEP) code. The optimized lattice parameters are well in accord with the existing synthesized values. The investigated elastic constants for this compound are positive which ensured the mechanical stability of this phase. The calculated values of Pugh’s ratio and Poisson’s ratio ensure the brittle character of SrCo2Si2. The universal anisotropic constant AU ensures the anisotropic behavior of SrCo2Si2.The softness nature of SrCo2Si2 is confirmed by the bulk modulus calculations. The overlapping of the valence band and conduction band near the Fermi level indicates the metallic nature of SrCo2Si2. At the Fermi level, the major contribution comes from Co-3d and Si-3p states. The large reflectivity in the high-energy region indicates that this compound might be useful as coating materials for reducing solar heating. The photoconductivity and absorption begins with zero photon energy which also ensures the metallic nature of SrCo2Si2.

Anisotropic constant-roll inflation with noncommutative model and swampland conjectures

In this paper, we study a constant-roll inflationary model in the presence of a noncommutative parameter with a homogeneous scalar field minimally coupled to gravity. The specific noncommutative inflation conditions proposed new consequences. On the other hand, we use anisotropic conditions and find new anisotropic constant-roll solutions with respect to noncommutative parameter. Also, we will plot some figures with respect to the specific values of the corresponding parameter and the swampland criteria which is raised from the exact potential obtained from the constant-roll condition. Finally, different of figures lead us to analyze the corresponding results and also show the effect of above mentioned parameter on the inflationary model.

Characterization of Co-Modified γ-Fe2O3 Based Composite Nanoparticles

During the synthesis of γ-Fe2O3 nanoparticles using a chemically-induced transition in a FeCl2 solution, Co-surface modification was attempted by adding Co (NO3)2 and NaOH to the solution. The magnetization behaviors, morphologies, crystal structure, and chemical compositions of the as-prepared samples were characterized using vibrating sample magnetometry, transmission electron microscopy, X-ray diffractometry, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The as-prepared particles consisted of γ-Fe2O3/CoFe2O4 composite crystallite and a CoCl2·6H2O coating. The molar, mass and volume ratios of the phases were estimated from the characterization results for each sample. The Co-modified γ-Fe2O3 nanoparticles’ anisotropic constant is approximately 1.48×10-1 J/cm3. Their coercivity depends on the size of composite crystallites, which is based on the γ-Fe2O3/CoFe2O4 content rather than the Co content.