Generalized Chern-Simons modified gravity in first-order formalism


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Ertem Ü., AÇIK Ö.

General Relativity and Gravitation, vol.45, no.2, pp.477-488, 2013 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 45 Issue: 2
  • Publication Date: 2013
  • Doi Number: 10.1007/s10714-012-1483-8
  • Journal Name: General Relativity and Gravitation
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.477-488
  • Keywords: Chern-Simons modified gravity, Nieh-Yan invariant, Torsion
  • Ankara University Affiliated: Yes

Abstract

We propose a generalization of Chern-Simons (CS) modified gravity in first-order formalism. CS modified gravity action has a term that comes from the chiral anomaly which is Pontryagin invariant. First-order CS modified gravity is a torsional theory and in a space-time with torsion the chiral anomaly includes a torsional topological term called Nieh-Yan invariant. We generalize the CS modified gravity by adding the Nieh-Yan term to the action and find the effective theory. We compare the generalized theory with the first-order CS modified gravity and comment on the similarities and differences. © 2012 Springer Science+Business Media New York.