On SL(2,R) symmetry in nonlinear electrodynamics theories

摘要

Recently, it has been observed that the Noether–Gaillard–Zumino (NGZ) identity holds order by order in α ′ expansion in nonlinear electrodynamics theories as Born–Infeld (BI) and Bossard–Nicolai (BN). The nonlinear electrodynamics theory that couples to an axion field is invariant under the S L ( 2 , R ) duality in all orders of α ′ expansion in the Einstein frame. In this paper we show that there are the S L ( 2 , R ) invariant forms of the energy momentum tensors of axion-nonlinear electrodynamics theories in the Einstein frame. These S L ( 2 , R ) invariant structures appear in the energy momentum tensors of BI and BN theories at all orders of α ′ expansion. The S L ( 2 , R ) symmetry appears in the BI and BN Lagrangians as a multiplication of Maxwell Lagrangian and a series of S L ( 2 , R ) invariant structures.