upposing there exists no new physics stabilizing the weak scale, the Standard Model Higgs potential exhibits a true vacuum at large field values, rendering the electroweak vacuum metastable (i.e., long lived relative to the age of the Universe). While this scenario need not preclude our current existence, it may not reconcile with a period of large(ish)-field inflation---large fluctuations in the Higgs field, induced by the inflationary energy density, can lead to the field locally sampling the unstable/true vacuum part of the potential, with potentially disastrous consequences. Evaluating the extent to which large-field inflation and the Higgs vacuum instability are incompatible requires understanding (i) how Higgs fluctuations evolve during inflation and (ii) the fate of large local fluctuations that sample the part of the potential beyond the barrier that separates the electroweak and true vacua. In this talk, I will discuss both of these aspects, and explain the implications for large-field inflation.

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