
Take home portion
... 9. Find examples of the following OR explain why no example exists. a. non-cyclic abelian group b. element of order 6 in Z 18 c. element of order 3 in Z 35 d. non-cyclic subgroup of Z 15 e. a cyclic group isomorphic to Z 3 Z 17 f. non-cyclic finite group g. cycle of length 6 in S 4 h. cycle of len ...
... 9. Find examples of the following OR explain why no example exists. a. non-cyclic abelian group b. element of order 6 in Z 18 c. element of order 3 in Z 35 d. non-cyclic subgroup of Z 15 e. a cyclic group isomorphic to Z 3 Z 17 f. non-cyclic finite group g. cycle of length 6 in S 4 h. cycle of len ...
TOPOLOGY WEEK 5 Proposition 0.1. Let (X, τ) be a topological
... Proposition 0.1. Let (X, τ ) be a topological space. A sequence (xn )n∈N converges to x ∈ X if and only if for every U ∈ τ such that x ∈ U ∃N ∈ N such that for every n ≥ N xn ∈ U . (equivalently, for every U ∈ τ such that x ∈ U there exists all but finitely many xn ∈ U . ) Definition 0.1. Let (X, τ ...
... Proposition 0.1. Let (X, τ ) be a topological space. A sequence (xn )n∈N converges to x ∈ X if and only if for every U ∈ τ such that x ∈ U ∃N ∈ N such that for every n ≥ N xn ∈ U . (equivalently, for every U ∈ τ such that x ∈ U there exists all but finitely many xn ∈ U . ) Definition 0.1. Let (X, τ ...
Simplicial Sets - Stanford Computer Graphics
... Homology of Simplicial Set • Chain complexes are the free abelian groups on the n-simplices • Boundary operator: (-1)i di • Degenerate (x = si y) complexes are 0 • Homology of Simplicial Set is the same as the homology of the simplicial complex ...
... Homology of Simplicial Set • Chain complexes are the free abelian groups on the n-simplices • Boundary operator: (-1)i di • Degenerate (x = si y) complexes are 0 • Homology of Simplicial Set is the same as the homology of the simplicial complex ...
Lecture 18: Groupoids and spaces The simplest algebraic invariant
... generalization is that we allow spaces of simplices rather than simply discrete sets of simplices. In other words, we also consider simplicial spaces. This leads naturally to topological categories, which we also introduce in this lecture. In subsequent lectures we will apply these ideas to bordism ...
... generalization is that we allow spaces of simplices rather than simply discrete sets of simplices. In other words, we also consider simplicial spaces. This leads naturally to topological categories, which we also introduce in this lecture. In subsequent lectures we will apply these ideas to bordism ...
Lecture IX - Functorial Property of the Fundamental Group
... Lecture IX - Functorial Property of the Fundamental Group We now turn to the most basic functor in algebraic topology namely, the π1 functor. Recall that the fundamental group of a space involves a base point and according to theorem (7.8) the fundamental group of a path connected space is unique up ...
... Lecture IX - Functorial Property of the Fundamental Group We now turn to the most basic functor in algebraic topology namely, the π1 functor. Recall that the fundamental group of a space involves a base point and according to theorem (7.8) the fundamental group of a path connected space is unique up ...
CATEGORIES AND COHOMOLOGY THEORIES
... Similarly, if products exist in ??‘?,one has a r-category SH@(S) associated to V with its product as composition: one defines e”(S) as the category of contravariant functors B(S) --f V which take disjoint unions to products. For a third example, if $9 is the category of modules over a commutative ri ...
... Similarly, if products exist in ??‘?,one has a r-category SH@(S) associated to V with its product as composition: one defines e”(S) as the category of contravariant functors B(S) --f V which take disjoint unions to products. For a third example, if $9 is the category of modules over a commutative ri ...
Some Notes on Compact Lie Groups
... A proof goes as follows. For any root α, we can find a subalgebra of the Lie algebra of G which is isomorphic to the Lie algebra of SU (2), and we can construct an SU (2) or SO(3) subgroup of G. This defines a map ϕα : S 3 → G. The main point is that if α is a long root, ϕα induces an isomorphism at ...
... A proof goes as follows. For any root α, we can find a subalgebra of the Lie algebra of G which is isomorphic to the Lie algebra of SU (2), and we can construct an SU (2) or SO(3) subgroup of G. This defines a map ϕα : S 3 → G. The main point is that if α is a long root, ϕα induces an isomorphism at ...
Homological algebra

Homological algebra is the branch of mathematics that studies homology in a general algebraic setting. It is a relatively young discipline, whose origins can be traced to investigations in combinatorial topology (a precursor to algebraic topology) and abstract algebra (theory of modules and syzygies) at the end of the 19th century, chiefly by Henri Poincaré and David Hilbert. The development of homological algebra was closely intertwined with the emergence of category theory. By and large, homological algebra is the study of homological functors and the intricate algebraic structures that they entail. One quite useful and ubiquitous concept in mathematics is that of chain complexes, which can be studied both through their homology and cohomology. Homological algebra affords the means to extract information contained in these complexes and present it in the form of homological invariants of rings, modules, topological spaces, and other 'tangible' mathematical objects. A powerful tool for doing this is provided by spectral sequences.From its very origins, homological algebra has played an enormous role in algebraic topology. Its sphere of influence has gradually expanded and presently includes commutative algebra, algebraic geometry, algebraic number theory, representation theory, mathematical physics, operator algebras, complex analysis, and the theory of partial differential equations. K-theory is an independent discipline which draws upon methods of homological algebra, as does the noncommutative geometry of Alain Connes.