Differentiable stack
In algebra, given a ring homomorphism , there are three ways to change the coefficient ring of a module; namely, for a right R-module M and a right S-module N,
- , the induced module.
- , the coinduced module.
- , the restriction of scalars.
They are related as adjoint functors:
and
This is related to Shapiro's lemma.
See also
References
- J.P. May, Notes on Tor and Ext