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The Lumenary
स्नातकोत्तर प्रथम वर्षAlgebraनियोजित

Modules

Modules over rings, submodules and quotients, exact sequences, free, projective and injective modules, tensor products, and the structure theorem for finitely generated modules over a principal ideal domain.

math.algebra.modules

इस विषय का पाठ अभी लिखा नहीं गया है। नीचे दी गई रूपरेखा पाठ्यक्रम-मानचित्र का हिस्सा है और इसकी समीक्षा नहीं हुई है।

इस पर आधारित

28 अनिवार्य पूर्वापेक्षाएँ (बिल्कुल नीचे तक)

आप सीखेंगे

  • Work with module homomorphisms, kernels, cokernels and exact sequences.
  • Prove the structure theorem for finitely generated modules over a PID, and deduce the classification of finitely generated abelian groups and the Jordan normal form.
  • Compute tensor products of modules and describe their effect on exact sequences.

परिभाषा

  • A module over a ring R is an abelian group with an action of R satisfying the distributive and associative laws.
  • A sequence A → B → C is exact at B if the image of the first map equals the kernel of the second.
  • A module P is projective if Hom(P, −) carries surjections to surjections.

प्रमेय

  • A finitely generated module over a PID R is isomorphic to a direct sum R/(d₁) ⊕ ⋯ ⊕ R/(dₖ) with d₁ | d₂ | ⋯ | dₖ.
  • Free modules are projective, and over a PID every submodule of a free module is free.
  • M ⊗_R − is right exact but in general not exact.

आम भ्रांतियाँ

  • Expecting modules to behave like vector spaces: ℤ/2ℤ is a ℤ-module with no basis.
  • Assuming tensoring preserves injectivity: multiplication by 2 on ℤ is injective, but becomes zero after tensoring with ℤ/2ℤ.

आगे ले जाता है

वैकल्पिक खोजें

  • Adjunctions The tensor–hom adjunction Hom(M ⊗ N, P) ≅ Hom(M, Hom(N, P)), natural in all three variables, is a basic example of an adjunction.

अधिगम पथ

आगे पढ़ने के लिए

  • David S. Dummit and Richard M. Foote, Abstract Algebra
  • Serge Lang, Algebra