Related papers: Can classical wormholes stabilize the brane-anti-b…
We study the dynamics of a general scalar field, a tachyon or an ordinary scalar, in the presence of world-volume massless fields in the DBI effective theory by exploring their exact solutions. The obtained solutions indicate that the…
We consider D-branes in group manifolds, from the point of view of open strings and using the Born-Infeld action on the brane worldvolume. D-branes correspond to certain integral (twined) conjugacy classes. We explain the integrality…
We revisit the effective low-energy dynamics of the volume modulus in warped flux compactifications with anti-D3-branes in order to analyze the prospects for meta-stable de Sitter vacua and brane inflation along the lines of KKLT/KKLMMT. At…
A basic constraint to be satisfied by Brans class I solution for being a traversible wormhole is derived. It is argued that the solution could be a wormhole analogue of the Horowitz-Ross naked black hole. It is further demonstrated that the…
We consider the Born-Infeld action for symmetry-preserving, orientable D-branes in compact group manifolds. We find classical solutions that obey the flux quantization condition. They correspond to conformally invariant boundary conditions…
A lower bound on the size of a Lorentzian wormhole can be obtained by semiclassically introducing the Planck cut-off on the magnitude of tidal forces (Horowitz-Ross constraint). Also, an upper bound is provided by the quantum field…
We construct new non-singular and time-dependent solutions from the black diholes with unbalanced magnetic charge. These solutions are constructed by the double Wick rotation with the analytic continuation of the mass or NUT-parameter of…
Some recent papers have claimed the existence of static, spherically symmetric wormhole solutions to gravitational field equations in the absence of ghost (or phantom) degrees of freedom. We show that in some such cases the solutions in…
We consider a system of D0-branes in toroidally compactified space with interactions described by a Born-Infeld-type generalisation of the leading v^2 + v^4/r^{D-4} terms (D is the number of non-compact directions in M-theory, including the…
We construct thin-shell electrically charged wormholes in d-dimensional general relativity with a cosmological constant. The wormholes constructed can have different throat geometries, namely, spherical, planar and hyperbolic. Unlike the…
We discover that a class of bubbles of nothing are embedded as time dependent scaling limits of previous spacelike-brane solutions. With the right initial conditions, a near-bubble solution can relax its expansion and open the compact…
We discuss the computation of the leading corrections to D-brane solutions due to higher derivative terms in the corresponding low energy effective action. We develop several alternative methods for analyzing the problem. In particular, we…
Linear stability of braneworld models constructed with multi-scalar fields is very different from that of single-scalar field models. It is well known that both the tensor and scalar perturbation equations of the later can always be written…
In their Letter [Phys. Rev. Lett. 126, 101102 (2021); arXiv: 2010.07317], J.L. Bl\'azquez-Salcedo, C. Knoll and E. Radu have constructed a very interesting class of wormhole solutions in GR, supported by a pair of classical charged spinor…
One can obtain very large classes of horizonless microstate geometries corresponding to near-extremal black holes by placing probe supertubes whose action has metastable minima inside certain supersymmetric bubbling solutions. We show that…
Analysing the static, spherically symmetric graviton-dilaton solutions in low energy string and Brans-Dicke theory, we find the following. For a charge neutral point star, these theories cannot predict non trivial PPN parameters, $\beta$…
We point out some intriguing analogies between field theoretic solitons (topological defects) and D-branes. Annihilating soliton-antisoliton pairs can produce stable solitons of lower dimensionality. Solitons that localize massless gauge…
We explore the possibility of dynamic wormhole geometries, within the context of nonlinear electrodynamics. The Einstein field equation imposes a contracting wormhole solution and the obedience of the weak energy condition. Furthermore, in…
We investigate the dynamics of dilatonic D-dimensional 0-branes in the near-horizon regime. The theory is given in a twofold form: two-dimensional dilaton gravity and nonlinear sigma model. Using asymptotic symmetries, duality relations,…
There is nothing to prevent a higher-dimensional anti-de Sitter bulk spacetime from containing various other branes in addition to hosting our universe, presumed to be a positive-tension 3-brane. In particular, it could contain closed,…