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Register a new userNon-singular and ghost-free infinite derivative gravity with torsion
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Added by
Francisco Jos\\'e Maldonado Torralba
Publication date
2018
fields
Physics
and research's language is
English
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We present the most general quadratic curvature action with torsion including infinite covariant derivatives and study its implications around the Minkowski background via the Palatini approach. Provided the torsion is solely given by the background axial field, the metric and torsion are shown to decouple, and both of them can be made ghost and singularity free for a fermionic source.
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In this paper we will construct a linearized metric solution for an electrically charged system in a {it ghost-free} infinite derivative theory of gravity which is valid in the entire region of spacetime. We will show that the gravitational potential for a point-charge with mass $m$ is non-singular, the Kretschmann scalar is finite, and the metric approaches conformal-flatness in the ultraviolet regime where the non-local gravitational interaction becomes important. We will show that the metric potentials are bounded below one as long as two conditions involving the mass and the electric charge are satisfied. Furthermore, we will argue that the cosmic censorship conjecture is not required in this case. Unlike in the case of Reissner-Nordstrom in general relativity, where $|Q|leq m/M_p$ has to be always satisfied, in {it ghost-free} infinite derivative gravity $|Q|>m/M_p$ is also allowed, such as for an electron.
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