$k$-Gauss-Bonnet Inflation. (arXiv:2107.05926v2 [gr-qc] UPDATED)
<a href="http://arxiv.org/find/gr-qc/1/au:+Pham_T/0/1/0/all/0/1">Tuyen M. Pham</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Nguyen_D/0/1/0/all/0/1">Duy H. Nguyen</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Do_T/0/1/0/all/0/1">Tuan Q. Do</a>

We propose a novel $k$-Gauss-Bonnet model, in which a kinetic term of scalar
field is allowed to non-minimally couple to the Gauss-Bonnet topological
invariant in the absence of a potential of scalar field. As a result, this
model is shown to admit an isotropic power-law inflation provided that the
scalar field is phantom. Furthermore, stability analysis based on the dynamical
system method is performed to indicate that this inflation solution is indeed
stable and attractive. More interestingly, a gradient instability in tensor
perturbations is shown to disappear in this model.

We propose a novel $k$-Gauss-Bonnet model, in which a kinetic term of scalar
field is allowed to non-minimally couple to the Gauss-Bonnet topological
invariant in the absence of a potential of scalar field. As a result, this
model is shown to admit an isotropic power-law inflation provided that the
scalar field is phantom. Furthermore, stability analysis based on the dynamical
system method is performed to indicate that this inflation solution is indeed
stable and attractive. More interestingly, a gradient instability in tensor
perturbations is shown to disappear in this model.

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