Let R be a commutative Noetherian ring and M, N be finitely generated R-modules. a) Define the tensor product M R N and prove that it is also a finitely generated R-module. Use the properties of finitely generated modules in your proof. b) Investigate the Tor functor by computing Tor (M, N) for specific modules M and N. Provide an explicit example and perform the computation. c) Define the projective dimension of a module and prove that if M has finite projective dimension, then Torr³ (M, N) = 0 for all n greater than the projective dimension of M. Close d) Explore the flatness of modules by proving that a module M is flat if and only if Tor (M, N) = 0 for all finitely generated R-modules N. Provide a detailed proof of this equivalence. e) Using the concept of homological dimension, determine the global dimension of a polynomial ring R[×1, x2, . . ., x] over a field R. Provide a comprehensive proof supporting your determination.

Elements Of Modern Algebra
8th Edition
ISBN:9781285463230
Author:Gilbert, Linda, Jimmie
Publisher:Gilbert, Linda, Jimmie
Chapter8: Polynomials
Section8.1: Polynomials Over A Ring
Problem 17E
icon
Related questions
Question
100%

I need gereneral proofs without AI, please give human solution, hand written if possible, and do before 4:45

Let R be a commutative Noetherian ring and M, N be finitely generated R-modules.
a) Define the tensor product M R N and prove that it is also a finitely generated R-module.
Use the properties of finitely generated modules in your proof.
b) Investigate the Tor functor by computing Tor (M, N) for specific modules M and N.
Provide an explicit example and perform the computation.
c) Define the projective dimension of a module and prove that if M has finite projective
dimension, then Torr³ (M, N) = 0 for all n greater than the projective dimension of M.
Close
d) Explore the flatness of modules by proving that a module M is flat if and only if
Tor (M, N) = 0 for all finitely generated R-modules N. Provide a detailed proof of this
equivalence.
e) Using the concept of homological dimension, determine the global dimension of a polynomial
ring R[×1, x2, . . ., x] over a field R. Provide a comprehensive proof supporting your
determination.
Transcribed Image Text:Let R be a commutative Noetherian ring and M, N be finitely generated R-modules. a) Define the tensor product M R N and prove that it is also a finitely generated R-module. Use the properties of finitely generated modules in your proof. b) Investigate the Tor functor by computing Tor (M, N) for specific modules M and N. Provide an explicit example and perform the computation. c) Define the projective dimension of a module and prove that if M has finite projective dimension, then Torr³ (M, N) = 0 for all n greater than the projective dimension of M. Close d) Explore the flatness of modules by proving that a module M is flat if and only if Tor (M, N) = 0 for all finitely generated R-modules N. Provide a detailed proof of this equivalence. e) Using the concept of homological dimension, determine the global dimension of a polynomial ring R[×1, x2, . . ., x] over a field R. Provide a comprehensive proof supporting your determination.
Expert Solution
steps

Step by step

Solved in 2 steps with 5 images

Blurred answer