Starobinsky-Bel-Robinson gravity. (arXiv:2205.13172v2 [gr-qc] UPDATED)
<a href="http://arxiv.org/find/gr-qc/1/au:+Ketov_S/0/1/0/all/0/1">Sergei V. Ketov</a>

A novel string-inspired gravitational theory in four spacetime dimensions is
proposed as a sum of the modified $(R+alpha R^2)$ gravity motivated by the
Starobinsky inflation and the leading Bel-Robinson-tensor-squared correction to
the gravitational effective action of superstrings/M-theory compactified down
to four dimensions. The possible origin of the theory from higher dimensions is
revealed. The proposed Starobinsky-Bel-Robinson action has only two free
parameters, which makes it suitable for verifiable physical applications in
black hole physics, cosmological inflation and Hawking radiation.

A novel string-inspired gravitational theory in four spacetime dimensions is
proposed as a sum of the modified $(R+alpha R^2)$ gravity motivated by the
Starobinsky inflation and the leading Bel-Robinson-tensor-squared correction to
the gravitational effective action of superstrings/M-theory compactified down
to four dimensions. The possible origin of the theory from higher dimensions is
revealed. The proposed Starobinsky-Bel-Robinson action has only two free
parameters, which makes it suitable for verifiable physical applications in
black hole physics, cosmological inflation and Hawking radiation.

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