wittFrobenius -- The (Witt) Frobenius map of a Witt ring

Usage:

phi = wittFrobenius W
Inputs:
- W, an instance of the type WittPolynomialRing or an instance of the type WittQuotientRing, The Witt ring of a ring R of positive characteristic
Outputs:
- phi, an instance of the type WittRingMap, the Frobenius map on W

Description

This gives the Frobenius map on the Witt ring W (which in coordinates is just the entry-wise Frobenius)

i1 : R = ZZ/5[x]

o1 = R

o1 : PolynomialRing

i2 : W = witt(2,R);

i3 : phi = wittFrobenius W;

wittFrobenius(WittPolynomialRing)
wittFrobenius(WittQuotientRing)
wittFrobenius(WittRingElement) -- The (Witt) Frobenius map on an element
wittFrobenius(ZZ,Ring) -- The (Witt) Frobenius map on the Witt vectors of a ring

The source of this document is in WittVectors/Documentation.m2:529:0.