Computational Complexity of Algorithms

Question

I want to know if the following proposition is correct or not?

For any integer k, there exists an problem P for which, the minimum possible time complexity of any solution algorithm is $\Omega(n^k)$

Please give me creditable sources such as journal papers, books, etc. about the solution of the above question.

UPDATE: By algorithm I mean standard algorithms as discussed in computational complexity. i.e. an algorithm that for any binary encoded input of size n which corresponds to a problem instance, outputs 0 or 1 (or true or false)

Thanks

Answer 1

Alternatively, look for the Time Hierarchy Theorem: http://en.wikipedia.org/wiki/Time_hierarchy_theorem