Courses ¨

INTRODUCTION TO HIGHER ALGEBRA
AND REPRESENTATION THEORY
(I.Yu.Tipunin)

  • Basic notions of linear algebra
    • Linear space, subspace, factor-space
    • Linear mappings between spaces, complexes, exact sequences
    • Direct sum and tensor product of linear spaces, linear functionals, dual space, tensors
    • Complexification and realization of linear spaces, real form
    • Grading and filtration on linear space
  • Basic algebraic systems
    • Associative algebras, Lie algebras
    • Mappings between algebras, homomorphisms, isomorphisms
    • Subalgebra, ideal and factor-algebra, simple and semi-simple algebras; Abelian, nilpotent, solvable and reductive Lie algebras
    • Short exact sequences of algebras
    • Algebras Matn (C), Matn (R), gl (n, C), gl (n, R)
    • Simplicity of algebras Matn (C) and Matn (R)
    • Notions of algebra module and algebra representation
    • Reducible, irreducible and completely reducible representations
    • Representation homomorphisms, intertwining operator, Schur's lemma
  • Theory of weight representations of sl (2, C)
    • Notions of highest weight representation, Verma module and contragradient module
    • Realization of the Verma module and its contragradient in polinomial space of one variable
    • Notion of singular vectors and its explicit finding
    • Finite-dimensional irreducible modules
    • Weight representations without highest weight
    • Extensions of representations
    • Examples of representations not being weight
  • Classical Lie groups and its Lie algebras
    • Definition of groups, group homomorphisms and isomorphisms, subgroups, normal subgroups
    • Permutation group, finite groups
    • Bi-linear forms which are invariant under group action
    • Classical Lie groups GL (n) , SL (n) , O (n) , SO (n) , Sp (n) ; Euclidean, Lorentz and Poincare groups; groups U (n) and SU (n)
    • Connection between Lie group and its Lie algebra for matrix groups
    • Lie algebras of classical Lie groups
    • Bi-linear forms which are invariant under Lie algebra action
    • Group action on a multitude, group representation, group orbits, adjoint and coadjoint group representation
    • Bi-linear forms on representations of Lie algebras and groups, Killing form
    • Cartan subgroup and subalgebras, Borel subgroup and subalgebras, top and bottom triangular subgroups and subalgebras, Gauss decomposition of classical groups and algebras
    • Enveloping algebras of Lie algebras
    • Free associative algebras and Lie algebras, algebra assignment by means of generatrices and relations
    • Enveloping algebra of representation, universal enveloping algebra
    • Poincare-Birkhoff-Witt basis
    • Connection between representations of Lie algebra and its universal eneveloping algebra
    • Universal eneveloping algebra of classical Lie algebras
    • Center of universal eneveloping algebra, Casimir operators and center of U (sl (2)) , universal eneveloping algebras of Lorentz and Poincare algebras
    • Notion of induced representation, Verma modules of classical Lie algebras
    • Tensor product of associative algebras and representations, notion of coproduct, coassociativity and cocommutativity, commutative diagrams, bi-algebras and Hopf algebra
    • Realization of universal enveloping algebra of Lie algebra as a space of generalized functions on group, structure of Hopf algebra on universal enveloping algebra of Lie algebra
    • Tensor products of algebra representations and contragradient modules
    • Tensor products of finite-dimensional irreducible representations of sl (2, C) , Klebsh-Gordan coefficients
  • Representations of classical Lie algebras in tensor spaces
    • Schur's duality, representation of symmetric group and Young diagram, types of symmetry
    • Anticommutative variables, Grassmann algebras, Clifford algebras, connection between Clifford algebras and matrix algebras, complex and real cases, notion of super Lie algebra, simplest examples, trace and supertrace on associative algebra
    • Spinors as Clifford algebra representations, charge-conjugate matrix, Majorana and Weyl spinors
    • Realization of representations of classical Lie algebras in boson and fermion Fock spaces
  • Elements of Cartan theory
    • Cartansubalgebras, root vectors, root decomposition, Chevalley's basis, lattices of roots and weights
    • Weight representations, representations of the highest and lowest weight, lattice of representation weights, character of representation, representation from " categories O "
    • Simple roots, Dynkin diagrams, classification of simple complex Lie algebras, reconstruction of Lie algebra using Dynkin diagram
    • Weyl group, Weyl chambers, prepotent weights, integral weights, elements of the structural theory of Verma modules , Jordan-Gelder series for Verma module, repetition factor of simple subfactors, singular vectors, Katz-Kazhdan theorem, structure of " categories O ", shift functor
  • Elements of homological algebra
    • Chevalley cohomologies of Lie algebras, interpretation of younger cohomological classes, central extensions, affine algebras, Virassaro algebra
    • Hochschield cohomologies, elements of deformation theory, deformed brackets
    • Some notions of category theory
    • Basic computational means: diagrammatic search, long exact sequences of cohomology, algebraical homotopy, resolvents and the simplest spectral sequences
    • Computing of cohomologies with coefficients lying in finite-dimesional irreducible representations for simple algebras and its subalgebras, Bernstein-Gelfand-Gelfand resolvent
  • Algebraical aspects of quantization
    • Poisson algebras, Poisson algebras deformations, notion of deformed quantization
    • Poisson-Lie groups, Sklyanin bracket, quantum groups
    • Quantum universal enveloping algebras of semi-simple Lie algebras, quasi-tensorial categories, universal R-matrix,Yang-Baxter equations
    • Quantum sl(2) and its representations in the root of the identity, infinite-dimensional center

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