Inspired by the recent works of S. Rao-S. Yang-X.-D. Yang and L. Meng on the blow-up formulae for de Rham and Morse-Novikov cohomology groups, we give a new simple proof of the blow-up formula for Morse-Novikov cohomology by introducing the relative Morse-Novikov cohomology group via sheaf cohomology theory and presenting the explicit isomorphism therein.

No abstract

No abstract

We give a new Tian-Todorov lemma on deformations of CR-structures and use it to reprove the deformation unobstructedness of normal compact strongly pseudoconvex CRmanifold under the assumption of d ′ d ′′ -lemma, more faithfully following Tian-Todorov's approach.