Abstract
We bound the symbol length of elements in the Brauer group of a field K containing a Cm field (for example any field containing an algebraically closed field or a finite field), and solve the local exponent-index problem for a Cm field F. In particular, for a Cm field F, we show that every F central simple algebra of exponent pt is similar to the tensor product of at most len(pt, F) ≤ t(pm−1−1) symbol algebras of degree pt. We then use this bound on the symbol length to show that the index of such algebras is bounded by (pt)(pm−1−1), which in turn gives a bound for any algebra of exponent n via the primary decomposition. Finally for a field K containing a Cm field F, we show that every F central simple algebra of exponent pt and degree ps is similar to the tensor product of at most len(pt, ps,K) ≤ len(pt, L) symbol algebras of degree pt, where L is a Cm+edL(A)+ps−t−1 field.
Original language | English |
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Pages (from-to) | 413-427 |
Number of pages | 15 |
Journal | Transactions of the American Mathematical Society |
Volume | 368 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2016 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2015 American Mathematical Society.