in the current paper, we have studied the effect of dark energy on for-mation where dark energy exists in the background. for this purpose, we used both wmap9 and planck data to study how the radius changes with redshift in these mod-els. we used different data sets to fix the cosmological parameters to obtain a solution for a spherical region under collapse. the mechanism of structure formation f...

 Casimir entropy is an important aspect of casimir effect and at the nanoscale is visible. In this paper, we employ the path integral method to ‎obtain a‎ ‎general‎ relation for casimir entropy and ‎i‎nternal energy of arbitrary shaped objects in the presence of two, three and four dimension scalar fields and ‎the‎ electromagnetic field. For this purpose, using Lagrangian and based on a perturb...

The problem of unbounded uniaxial chiral omega media in the presence of both static electric and magnetic point charges is investigated. For this purpose scalar electric and magnetic potentials in these media are introduced. Using these potentials, the corresponding electric and magnetic fields are determined. The similar problem of static electric and magnetic current sources with the goal of ...

In this paper, we investigate the cosmological dynamics in a spatially flat Friedmann–Lemaître–Robertson–Walker geometry scalar-tensor and scalar-torsion theories where nonminimally coupled scalar field is complex field. We derive equations make use of dimensionless variables order to determine stationary points their stability properties. The physical properties are discussed while find that t...