1995/07/03 by D. V. Gal'tsov, D.V. Gal’tsov, Oleg V. Kechkin +1 · 4 citations
Mathematics · Physics and Astronomy · #Axion #Black Holes and Theoretical Physics #Combinatorics #Cosmology and Gravitation Theories #Dilaton #Duality (order theory) #Killing vector field #Mathematical physics #Mathematics #Noncommutative and Quantum Gravity Theories #Particle physics #Physics #hep-th
paper · pdf · doi:10.1103/physrevd.54.1656
published as Phys.Rev. D54 (1996) 1656-1666 · LATEX, 20 pages, no figures
arxiv created 1995/07/03 · openalex publication_date 1996/07/15 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study a bosonic four-dimensional effective action corresponding to the heterotic string compactified on a six-torus (dilaton-axion gravity with one vector field) on a curved space-time manifold possessing a timelike Killing vector field. Previously the existence of the SO(2, 3)\ensuremath∼Sp(4, R) global symmetry (U duality) as well as the symmetric space property of the corresponding \ensuremathσ model have been established following the Neugebauer-Kramer approach. Here we present an explicit form of the Sp(4, R) generators in terms of coset variables and construct a representation of the coset in terms of the physical target space coordinates. A complex symmetric 2 \ifmmode×\else\texttimes\fi 2 matrix Z ("matrix dilaton-axion") is then introduced for which U duality takes the matrix-valued SL(2, R) form. In terms of this matrix the theory is further presented as a K"ahler \ensuremathσ model. This leads to a more economic 2 \ifmmode×\else\texttimes\fi 2 formulation suggesting some new solution-generating techniques. A new solution (corresponding to constant ImZ) is obtained which describes the system of point massless magnetic monopoles endowed with axion charges. In such a system mutual magnetic repulsion is exactly balanced by axion attraction so that the resulting space-time is locally flat but possesses multiple Taub-NUT singularities.