3+1-dimensional thin-shell wormhole with deformed throat can be supported by normal matter

From physics standpoint exotic matter problem is a major difficulty in thin-shell wormholes (TSWs) with spherical / cylindrical throat topologies. We aim to circumvent this handicap by considering angular dependent throats in $3+1-$dimensions. By considering the throat of the TSW to be deformed spherical, i.e., a function of $\theta$ and $\varphi$, we present general conditions which are to be satisfied by the shape of the throat in order to have the wormhole supported by matter with positive density in the static reference frame. We provide particular solutions / examples to the constraint conditions.Comment: 7 pages two figures. Retitled and additional material added, accepted for publication in EPJ

Solution for Static, Spherically Symmetric Lovelock Gravity Coupled with Yang-Mills Hierarchy

The hierarchies of both Lovelock gravity and power-Yang-Mills field are combined through gravity in a single theory. In static, spherically symmetric ansatz exact particular integrals are obtained in all higher dimensions. The advantage of such hierarchies is the possibility of choosing coefficients, which are arbitrary otherwise, to cast solutions into tractable forms. To our knowledge the solutions constitute the most general spherically symmetric metrics that incorporate complexities both of Lovelock and Yang-Mills hierarchies within the common context. A large portion of our general class of solutions concern and addresses to black holes for which specific examples are given. Thermodynamical behaviors of the system is briefly discussed in particular dimensions.Comment: 10 pages, no figures, to appear in PL

A topological metric in 2+1-dimensions

Real-valued triplet of scalar fields as source gives rise to a metric which tilts the scalar, not the light cone, in 2+1-dimensions. The topological metric is static, regular and it is characterized by an integer $\kappa =\pm 1,\pm 2,...$. The problem is formulated as a harmonic map of Riemannian manifolds in which the integer $\kappa$ equals to the degree of the map.Comment: 4 pages no figure, final version accepted for publication in EPJ

Black holes from multiplets of scalar fields in 2+1- and 3+1-dimensions

We obtain classes of black hole solutions constructed from multiplets of scalar fields in 2+1 / 3+1 dimensions. The multi-component scalars don't undergo a symmetry breaking so that only the isotropic modulus is effective. The Lagrangian is supplemented by a self-interacting potential which plays significant role in obtaining the exact solutions. In 2+1 / 3+1 dimensions doublet / triplet of scalars is effective which enriches the available black hole spacetimes and creates useful Liouville weighted field theoretic models.Comment: 10 pages, 10 figures, final version accepted for publication in EPJ

A quasi-free position-dependent-mass jump and self-scattering correspondence

A quasi-free quantum particle endowed with Heaviside position dependent mass jump is observed to experience scattering effects manifested by its by-product introduction of the derivative of the Dirac's-delta point dipole interaction. Using proper parametric mappings, the reflection and transmission coefficients are obtained. A new ordering ambiguity parameters set, as the only feasibly admissible within the current methodical proposal, is suggested.Comment: 13 pages, no figure