TY - JOUR A1 - Murray, Riley A1 - Naumann, Helen A1 - Theobald, Thorsten T1 - Sublinear circuits and the constrained signomial nonnegativity problem T2 - Mathematical programming : Series A, Series B N2 - Conditional Sums-of-AM/GM-Exponentials (conditional SAGE) is a decomposition method to prove nonnegativity of a signomial or polynomial over some subset X of real space. In this article, we undertake the first structural analysis of conditional SAGE signomials for convex sets X. We introduce the X-circuits of a finite subset A⊂Rn , which generalize the simplicial circuits of the affine-linear matroid induced by A to a constrained setting. The X-circuits serve as the main tool in our analysis and exhibit particularly rich combinatorial properties for polyhedral X, in which case the set of X-circuits is comprised of one-dimensional cones of suitable polyhedral fans. The framework of X-circuits transparently reveals when an X-nonnegative conditional AM/GM-exponential can in fact be further decomposed as a sum of simpler X-nonnegative signomials. We develop a duality theory for X-circuits with connections to geometry of sets that are convex according to the geometric mean. This theory provides an optimal power cone reconstruction of conditional SAGE signomials when X is polyhedral. In conjunction with a notion of reduced X-circuits, the duality theory facilitates a characterization of the extreme rays of conditional SAGE cones. Since signomials under logarithmic variable substitutions give polynomials, our results also have implications for nonnegative polynomials and polynomial optimization. KW - Sums of arithmetic-geometric exponentials KW - Positive signomials KW - Exponential sums KW - Sums of nonnegative circuit polynomials (SONC) KW - Positive polynomials KW - Multiplicative convexity KW - Log convex sets Y1 - 2022 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/69563 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-695634 SN - 1436-4646 N1 - Open Access funding enabled and organized by Projekt DEAL. N1 - Mathematics Subject Classification: Primary 14P05, 90C23, Secondary 05B35 VL - 198 IS - 1 SP - 471 EP - 505 PB - Springer CY - Berlin ; Heidelberg ER -