D-Branes in Para-Hermitian Geometries

Abstract

We introduce T-duality invariant versions of D-branes in doubled geometry using a global covariant framework based on para-Hermitian geometry and metric algebroids. We define D-branes as conformal boundary conditions for the open string version of the Born sigma-model, where they are given by maximally isotropic vector bundles which do not generally admit the standard geometric picture in terms of submanifolds. When reduced to the conventional sigma-model description of a physical string background as the leaf space of a foliated para-Hermitian manifold, integrable branes yield D-branes as leaves of foliations which are interpreted as Dirac structures on the physical spacetime. We define a notion of generalised para-complex D-brane, which realises our D-branes as para-complex versions of topological A/B-branes. We illustrate how our formalism recovers standard D-branes in the explicit example of reductions from doubled nilmanifolds.

Poisson-Lie T-duality defects and target space fusion

“…reminiscent of how D-brane compatible with extended supersymmetry [49], D-branes in para-Hermitian geometry [50] or complex submanifolds in generalised complex geometry [43] are characterised.…”

The invariant action for solitonic 5-branes

“…Along these line in the work [6] Dp-branes have been shown to correspond to Dirac structures on the subspace. Recently a similar approach based on Born sigma-models and para-Hermitian geometry has been considered in [36], where Dp-branes are identified with maximally isotropic vector bundles. Interesting is that these might not admit the standard geometric picture in terms of submanifolds, which could be a signature of possible dependence on dual coordinates, relating this approach to the picture based on generalized Killing vectors.…”

“…Several steps in this direction have been made for T-duality brane orbits with given dependence of tension on g s , which is a natural approach since T-duality does not mix them. To be mentioned are the works [2,3] considering covariant description of D p-branes in terms of maximally isotropic submanifolds in the doubled space, the work [36] describing D-branes in terms of Born sigma models (see [42] for a similar approach to branes of M-theory), the works [20,31] focusing on g −2 s (solitonic) branes and [9] addressing double field theory description of Wess-Zumino terms for various branes with tension down to g −4 s . Relevant for the present discussion are the works [9,20].…”

GEANT4 simulations for γ-ray detector array design for inplasma β-decays studies of nuclear astrophysics interest

“…If confirmed, these evidences are expected to have a huge impact in the study of nuclear-astrophysics processes and cosmology (BBN, s-processing, Cosmo-chronometers, Early Solar System formation) [5][6][7][8][9]. The PANDORA (Plasma for Astrophysics, Nuclear Decay Observation and Radiation for Archaeometry) project [10], supported by the INFN, proposes a new experimental approach to measure the variation of the half-life of β-decaying nuclei in the magnetically confined ECR plasma, correlating the decaying rate with thermodynamic plasma properties. ECR plasmas can be maintained in a dynamic-equilibrium for weeks with on-average constant local electron density n e and temperature T e (n e ∼ 10 11 −10 13 cm −3 , T e −0.1−100keV), which univocally determine the ion charge state distribution (CSD).…”