Title: Pfaffian formulas and Schur Q-function identities
Abstract: We establish Pfaffian analogues of the Cauchy–Binet formula and the Ishikawa–Wakayama minor-summation formula. Each of these Pfaffian analogues expresses a sum of products of subpfaffians of two skew-symmetric matrices in terms of a single Pfaffian. By using these Pfaffian formulas we give transparent proofs to several identities for Schur Q-functions.