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Abstract
摘要 |
Instantons are amongst the most important exact solutions studied in gauge theory, general relativity and theoretical physics generally, finding diverse application across a wide array of settings. From a gauge-theoretic perspective supergravity and string theory are notable by virtue of their local supersymmetry, which necessitates a fermionic gauge field, the gravitino. The presence of such a field then implies the existence of a previously unexplored class of instanton, which, unlike known non-perturbative phenomena, is fermionic in nature. Reporting the findings of 1604.05400, we demonstrate the existence of these solutions, along with their explicit construction from combinations of (anti)self-dual Yang-Mills gauge fields and Killing spinors. In so doing we provide an extensive new class of topologically non-trivial, half-BPS solutions in supergravity and string theory. Unlike the vast majority of known supersymmetric backgrounds these solutions possess non-vanishing fermionic character, and so generate and are in turn intrinsically dependent upon spacetime torsion. By virtue of their construction they also allow many aspects of conventional Yang-Mills instanton calculus to be repurposed into the locally supersymmetric setting, such that we may provide all possible solutions on certain gravitational backgrounds. We motivate and discuss these points, and indicate directions for future research. |
