English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

The extended scalar-tensor and vector-tensor theories admit black holesolutions with the nontrivial profiles of the scalar and vector fields,respectively. The disformal transformation maps a solution in a class of thescalar-tensor or vector-tensor theories to that in another class, and hence itcan be a useful tool to construct a new nontrivial solution from the known one.First, we investigate how the stationary and axisymmetric solutions in thevector-tensor theories without and with the $U(1)$ gauge symmetry aredisformally transformed. We start from a stationary and axisymmetric solutionsatisfying the circularity conditions, and show that in both the cases themetric of the disformed solution in general does not satisfy the circularityconditions. Using the fact that a solution in a class of the vector-tensortheories with the vanishing field strength is mapped to that in a class of theshift-symmetric scalar-tensor theories, we derive the disformed stationary andaxisymmetric solutions in a class of these theories, and show that the metricof the disformed solutions does not satisfy the circularity conditions if thescalar field depends on the time or azimuthal coordinate. We also confirm thatin the scalar-tensor theories without the shift symmetry, the disformedstationary and axisymmetric solutions satisfy the circularity conditions.Second, we investigate the disformal transformations of the stationary andaxisymmetric black hole solutions in the generalized Proca theory with thenonminimal coupling to the Einstein tensor, the shift-symmetric scalar-tensortheory with the nonminimal derivative coupling to the Einstein tensor, theEinstein-Maxwell theory, and the Einstein-conformally coupled scalar fieldtheory. We show that the disformal transformations modify the causal propertiesof the spacetime.

Disformal transformation of stationary and axisymmetric solutions in modified gravity