Use open mapping theorem to prove that the inverse of an invertible bounded linear map from Banach space X to Banach space Y is bounded.

I need simple implications of known theorems here to prove this.

Open mapping theorem: If X and Y are Banach spaces and A is a continuous linear surjection then A(G) is open in Y whenever G is open in X.

  • 1
    $\begingroup$ This is immediate from the theorem and the definition of "continuous" in terms of open sets. $\endgroup$ – David C. Ullrich Nov 23 '17 at 17:58

In functional analysis, boundedness of linear map is same as continuity of map.

As linear map is bounded invertible (so Surjective), then by open mapping theorem linear map is open map. Hence inverse of the map is continuous which is equivalent to boundedness of map.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.