In deformation theory, a branch of mathematics, Deligne's conjecture is about the operadic structure on Hochschild cochain complex. Various proofs have been suggested by Dmitry Tamarkin, [1] [2] Alexander A. Voronov, [3] James E. McClure and Jeffrey H. Smith, [4] Maxim Kontsevich and Yan Soibelman, [5] and others, after an initial input of construction of homotopy algebraic structures on the Hochschild complex. [6] [7] It is of importance in relation with string theory.