
"One-parameter subgroups of topological abelian groups". Topology
... Annihilators are the particularizations for subgroups of the more general notion of polars of subsets. Namely, for A ⊂ G and B ⊂ G∧ , the polar of A is A := {ϕ ∈ G∧ : ϕ(A) ⊂ T+ } and the inverse polar of B is B := {g ∈ G: ϕ(g) ∈ T+ , ∀ϕ ∈ B}, where T+ := {z ∈ T : Re z ≥ 0}. For a topological abel ...
... Annihilators are the particularizations for subgroups of the more general notion of polars of subsets. Namely, for A ⊂ G and B ⊂ G∧ , the polar of A is A := {ϕ ∈ G∧ : ϕ(A) ⊂ T+ } and the inverse polar of B is B := {g ∈ G: ϕ(g) ∈ T+ , ∀ϕ ∈ B}, where T+ := {z ∈ T : Re z ≥ 0}. For a topological abel ...
A survey of categorical concepts
... One easily checks that functors can themselves be composed, and in this way Cat becomes a category with functors as its arrows. Two categories are isomorphic if they are isomorphic as objects of Cat. We shall see below that this is not a very useful notion. ...
... One easily checks that functors can themselves be composed, and in this way Cat becomes a category with functors as its arrows. Two categories are isomorphic if they are isomorphic as objects of Cat. We shall see below that this is not a very useful notion. ...
Notes about Filters
... It can be shown that Ω is left adjoint to pt and the images of the two functors can be characterized as indicated in the theorem. Definition 57. The spectrum Spec(R) of a commutative ring R is the set of proper prime ideals of R with the Zariski topology, whose closed sets are of the form V (I) = {P ...
... It can be shown that Ω is left adjoint to pt and the images of the two functors can be characterized as indicated in the theorem. Definition 57. The spectrum Spec(R) of a commutative ring R is the set of proper prime ideals of R with the Zariski topology, whose closed sets are of the form V (I) = {P ...
CONVERGENT SEQUENCES IN TOPOLOGICAL SPACES 1
... 3. If X is equipped with the trivial topology T = {∅, X} then any sequence in X is convergent and its limit is any point in X. 4. Let X = R be given the finite complement topology. Convince yourself that the sequence xn = n converges to x0 = 1. Does this still remain true if instead we let X have th ...
... 3. If X is equipped with the trivial topology T = {∅, X} then any sequence in X is convergent and its limit is any point in X. 4. Let X = R be given the finite complement topology. Convince yourself that the sequence xn = n converges to x0 = 1. Does this still remain true if instead we let X have th ...
An Uncertainty Principle for Topological Sectors
... Suppose à is in a state of de¯nite magnetic ° ux m 2 H ` (X ; Z): · ` (X ) m . the support of the wavefunction à is in the topological sector H Such a state cannot be in an eigenstate of translations by flat characters, if there are any flat, but topologically nontrivial fields. Translation by such ...
... Suppose à is in a state of de¯nite magnetic ° ux m 2 H ` (X ; Z): · ` (X ) m . the support of the wavefunction à is in the topological sector H Such a state cannot be in an eigenstate of translations by flat characters, if there are any flat, but topologically nontrivial fields. Translation by such ...
Algebra 1 ELG HS.A.3: Perform arithmetic operations on polynomials.
... o 6.EE.A.4 Apply the properties of operations to generate equivalent expressions. For example, apply the distributive property to the expression 3 (2 + x) to produce the equivalent expression 6 + 3x; apply the distributive property to the expression 24x + 18y to produce the equivalent expression 6 ( ...
... o 6.EE.A.4 Apply the properties of operations to generate equivalent expressions. For example, apply the distributive property to the expression 3 (2 + x) to produce the equivalent expression 6 + 3x; apply the distributive property to the expression 24x + 18y to produce the equivalent expression 6 ( ...
H10
... Remark. One can also show that every finitely generated flat module is projective, so for finitely generated A-modules flat and projective are equivalent. However, there are (non-finitely generated) flat modules which are not projective. For example, the ring Z[ 12 ] is a flat module over Z, but not ...
... Remark. One can also show that every finitely generated flat module is projective, so for finitely generated A-modules flat and projective are equivalent. However, there are (non-finitely generated) flat modules which are not projective. For example, the ring Z[ 12 ] is a flat module over Z, but not ...
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.