Phase and stability of black strings in Einstein-Gauss-Bonnet theory at large D

The phase and stability of black strings in the Einstein-Gauss-Bonnet (EGB) theory are investigated by using the large D effective theory approach. The spacetime metric and thermodynamics are derived up to the next-to-leading order (NLO) in the 1/D expansion. We find that the entropy current defined by the Iyer-Wald formula follows the second law. As in the Einstein theory, the entropy difference from the total mass produces an entropy functional for the effective theory. Including the NLO correction, we find that for the large Gauss-Bonnet coupling constant alpha(GB), the Gregory-Laflamme instability of uniform black strings needs longer wavelength. Moreover, we show that the critical dimension, beyond which non-uiform black strings becomes more stable than uniform ones, increases as alpha(GB) becomes large, and approaches to a finite value for alpha(GB)-> infinity.

Automated summary

In this study, the phase and stability of black strings in the Einstein-Gauss-Bonnet (EGB) theory were investigated using the large D effective theory approach. The spacetime metric and thermodynamics were derived up to the next-to-leading order (NLO) in the 1/D expansion. It was found that the entropy current defined by the Iyer-Wald formula follows the second law. Similar to the Einstein theory, the entropy difference from the total mass produces an entropy functional for the effective theory. Including the NLO correction, it was discovered that the Gregory-Laflamme instability of uniform black strings requires longer wavelengths for large Gauss-Bonnet coupling constant alpha(GB). Moreover, it was shown that the critical dimension, beyond which non-uniform black strings become more stable than uniform ones, increases as alpha(GB) becomes large, and approaches a finite value for alpha(GB)-> infinity.