Verschiebung operator
In mathematics, the Verschiebung or Verschiebung operator V is a homomorphism between affine commutative group schemes over a field of nonzero characteristic p. For finite group schemes it is the Cartier dual of the Frobenius homomorphism. It was introduced by as the shift operator on Witt vectors taking to.
The Verschiebung operator V and the Frobenius operator F are related by FV = VF = , where is the pth power homomorphism of an abelian group scheme.
Examples
- If G is the discrete group with n elements over the finite field Fp of order p, then the Frobenius homomorphism F is the identity homomorphism and the Verschiebung V is the homomorphism . Its dual is the group scheme of nth roots of unity, whose Frobenius homomorphism is and whose Verschiebung is the identity homomorphism.
- For Witt vectors, the Verschiebung takes to.
- On the Hopf algebra of symmetric functions, the Verschiebung Vn is the algebra endomorphism that takes the complete symmetric function hr to hr/''n if n'' divides r and to 0 otherwise.