On the Complexity of Searching Maximum of a Function on a Quantum   Computer
  We deal with a problem of finding maximum of a function from the Holder class on a quantum computer. We show matching lower and upper bounds on the complexity of this problem. We prove upper bounds by constructing an algorithm that uses the algorithm for finding maximum of a discrete sequence. To prove lower bounds we use results for finding logical OR of sequence of bits. We show that quantum computation yields a quadratic speed-up over deterministic and randomized algorithms. 
Maciej Gocwin