| We examine in detail the stable reduction of three-point G-Galois covers of the projective line over a complete discrete valuation field of mixed characteristic (0, p), where G has a cyclic p-Sylow subgroup. In particular, we obtain results about ramification of primes in the minimal field of definition of the stable model of such a cover, under certain additional assumptions on G (one such sufficient, but not necessary set of assumptions is that G is solvable and p ≠ 2). This has the following consequence: Suppose f : Y → P1 is a three-point G-Galois cover defined over C , where G has a cyclic p-Sylow subgroup of order pn, and these additional assumptions on G are satisfied. Then the nth higher ramification groups above p for the upper numbering for the extension K/Q vanish, where K is the field of moduli of f. |
