2016/11/04 by Bhaskhar, Nivedita, Haase, Bastian · 1 citation
#11R58 (Secondary) #16K50 (Primary) #FOS: Mathematics #Number Theory (math.NT) #Rings and Algebras (math.RA)
paper · doi:10.48550/arxiv.1611.01248
Let K be a complete discretely valued field of characteristic 0 with residue field k of characteristic p. Let n=[k:kp] be the p-rank of k. It was proved by Parimala and Suresh that the Brauer p-dimension of K lies between n/2 and 2n. For n< 4, we improve the upper bound to n+1 and provide examples to show that our bound is sharp. For n < 3, we also improve the lower bound to n. For general n, we construct a family of fields Kn with residue fields of p-rank n, such that Kn admits a central simple algebra Dn of index pn+1. Our sharp lower bounds for n<3 and upper bounds for n< 4 in combination with the nature of these examples motivate us to conjecture that the Brauer p-dimension of such fields always lies between n and n+1.