Speaker
Description
It was recently suggested in [arXiv:1910.08555] that the spherical D6 brane solution of supergravity is dual to SYM on $S^7$ at small negative 't Hooft coupling. With the present work we investigate what happens to the SYM theory as one takes it from the true weak coupling regime through strong coupling to small negative coupling. Our guide is the simpler case of SYM on $S^5$, highlighting the importance of contact instantons in this regime and showing how this information can be extracted from the localized partition function. We motivate a conjecture for the contact instanton contribution to the partition function of SYM on squashed $S^7$ and study this partition function in the small negative $g_{YM}^2$ limit. We observe that three dimensional membranes contribute to the partition function in this limit, suggesting a dual description in terms of 7d gauged supergravity.
