Surgery Approach to Rudyak's Conjecture

Using the surgery we prove the following: THEOREM. Let $f:M\to N$ be a normal map of degree one between closed manifolds with $N$ being $(r-1)$-connected, $r\ge 1$. If $N$ satisfies the inequality $\dim N \leq 2r \cat N - 3$,thenfortheLusternik-Schnirelmanncategory$\cat M \geq \cat N$ .