1 Introduction 2 Compact group actions
... – Find a simplicial action Zpq on S 3 = S 1 ∗ S 1 without stationary points obtained by joining action of Zp on S 1 and Zq on the second S 1 . – Find an equivariant simplicial map h : S 3 → S 3 which is homotopically trivial. – Build the infinite mapping cylinder which is contactible and imbed it in ...
... – Find a simplicial action Zpq on S 3 = S 1 ∗ S 1 without stationary points obtained by joining action of Zp on S 1 and Zq on the second S 1 . – Find an equivariant simplicial map h : S 3 → S 3 which is homotopically trivial. – Build the infinite mapping cylinder which is contactible and imbed it in ...
Midterm solutions.
... The Bolzano Weierstrass theorem asserts that closed bounded intervals in R are sequentially compact. Assuming only this theorem, prove that closed balls in R3 are sequentially compact. Let C be a closed ball in R3 of radius r, centred at (a, b, c) and (xn , yn , zn ) be a sequence in C . Since (xn − ...
... The Bolzano Weierstrass theorem asserts that closed bounded intervals in R are sequentially compact. Assuming only this theorem, prove that closed balls in R3 are sequentially compact. Let C be a closed ball in R3 of radius r, centred at (a, b, c) and (xn , yn , zn ) be a sequence in C . Since (xn − ...
8. COMPACT LIE GROUPS AND REPRESENTATIONS 1. Abelian
... hence |gik | ≤ 1. This shows that U (n) is compact. Since SU (n) = det−1 (1) ⊂ U (n) is a closed subset of U (n), SU (n) is compact as well. 4.3. The connected component. If G is compact, then G0 C G is both open and closed in G. a) In particular, this shows that G0 is compact as well. b) The open c ...
... hence |gik | ≤ 1. This shows that U (n) is compact. Since SU (n) = det−1 (1) ⊂ U (n) is a closed subset of U (n), SU (n) is compact as well. 4.3. The connected component. If G is compact, then G0 C G is both open and closed in G. a) In particular, this shows that G0 is compact as well. b) The open c ...
Semidefinite and Second Order Cone Programming Seminar Fall 2012 Lecture 10
... and B. When we change basis for A, it is tantamount to replacing L (x) with L (Fx) where F is the change of basis matrix. Similarly changing basis in B is the same as replacing L (x) with L (x)G, where G is the change of basis matrix in B. Needless to say, the resulting algebras are all isomorph ...
... and B. When we change basis for A, it is tantamount to replacing L (x) with L (Fx) where F is the change of basis matrix. Similarly changing basis in B is the same as replacing L (x) with L (x)G, where G is the change of basis matrix in B. Needless to say, the resulting algebras are all isomorph ...
Note on exponential and log functions.
... All of this may seem rather roundabout, but it is simpler than the supposedly elementary approach in the text, which hides a lot of technical difficulties. Here is the outline of the supposedly elementary approach. (1) Given a positive number a 6= 1, one defines am/n in the elementary way for ration ...
... All of this may seem rather roundabout, but it is simpler than the supposedly elementary approach in the text, which hides a lot of technical difficulties. Here is the outline of the supposedly elementary approach. (1) Given a positive number a 6= 1, one defines am/n in the elementary way for ration ...
LIE GROUPS AND LIE ALGEBRAS – A FIRST VIEW 1. Motivation
... is a homomorphism of groups. This mapping is called the adjoint representation of G in g. Due to our definition of Lie groups this mapping is smooth. If we identify as usual the tangent space at 1 of GL(g) with End(g), then we obtain the linear mapping ad := T1 Ad : g → End(g). For each X, Y ∈ g we ...
... is a homomorphism of groups. This mapping is called the adjoint representation of G in g. Due to our definition of Lie groups this mapping is smooth. If we identify as usual the tangent space at 1 of GL(g) with End(g), then we obtain the linear mapping ad := T1 Ad : g → End(g). For each X, Y ∈ g we ...
Practice Exam 1
... same.) [3] Let G be the group of 2 by 2 matrices whose entries are integers mod 7, and whose determinant is nonzero mod 7. Let H be the subset of G consisting of all matrices whose determinant is 1 mod 7. (a) How many elements are there in G and in H? (b) Show that H is a normal subgroup of G. (c) W ...
... same.) [3] Let G be the group of 2 by 2 matrices whose entries are integers mod 7, and whose determinant is nonzero mod 7. Let H be the subset of G consisting of all matrices whose determinant is 1 mod 7. (a) How many elements are there in G and in H? (b) Show that H is a normal subgroup of G. (c) W ...
5.5 Basics IX : Lie groups and Lie algebras
... with non-zero determinant. It is a smooth manifold of dimension n2 , since it is an open subset of ...
... with non-zero determinant. It is a smooth manifold of dimension n2 , since it is an open subset of ...
UE Funktionalanalysis 1
... exists and defines a bounded linear operator. 18. Let {uj } be some orthonormal basis. Show that a bounded linear operator A is uniquely determined by its matrix elements Ajk = huj , Auk i with respect to this basis. 19. Show that an orthogonal projection PM 6= 0 has norm one. ...
... exists and defines a bounded linear operator. 18. Let {uj } be some orthonormal basis. Show that a bounded linear operator A is uniquely determined by its matrix elements Ajk = huj , Auk i with respect to this basis. 19. Show that an orthogonal projection PM 6= 0 has norm one. ...
Section 7.2
... Thus the columns u1, ..., un are orthogonal eigenvectors of A; and they form a basis for V . For a Hermitian matrix A, the eigenvalues are all real; and there is an orthogonal basis for the associated vector space V consisting of eigenvectors of A. In dealing with such a matrix A in a problem, the b ...
... Thus the columns u1, ..., un are orthogonal eigenvectors of A; and they form a basis for V . For a Hermitian matrix A, the eigenvalues are all real; and there is an orthogonal basis for the associated vector space V consisting of eigenvectors of A. In dealing with such a matrix A in a problem, the b ...
Functions C → C as plane transformations
... −1 is denoted i by mathematicians and j by physicists and engineers. Square roots of negative real numbers have no meaning in the real domain, yet were useful in formally manipulating formulas for the solutions of polynomial equations. 3 Complex arithmetic was worked out in l’Agebra (1560, pub. 1572 ...
... −1 is denoted i by mathematicians and j by physicists and engineers. Square roots of negative real numbers have no meaning in the real domain, yet were useful in formally manipulating formulas for the solutions of polynomial equations. 3 Complex arithmetic was worked out in l’Agebra (1560, pub. 1572 ...
Rigid Transformations
... The concept of manifold generalizes the concepts of curve, area, surface, and volume in the Euclidean space/plane … but not only … A manifold does not have to be a subset of a bigger space, it is an object on its own. A manifold is one of the most generic objects in math.. Almost everyth ...
... The concept of manifold generalizes the concepts of curve, area, surface, and volume in the Euclidean space/plane … but not only … A manifold does not have to be a subset of a bigger space, it is an object on its own. A manifold is one of the most generic objects in math.. Almost everyth ...
Linear and Bilinear Functionals
... This will be true iff we have λi > 0 for all i. Thus, a positive definite bilinear functional has positive definite eigenvalues. ...
... This will be true iff we have λi > 0 for all i. Thus, a positive definite bilinear functional has positive definite eigenvalues. ...
The Tangent Space of a Lie Group – Lie Algebras • We will see that
... and the third one is the canonical vector space identification. – By a straightforward coordinate calcultion we see that the brackets are also preserved. Example 3. Let V be a vector space of dimension n. Let End(V ) =the set of all linear maps from V to itself ∼ = M (n, R), Aut(V ) =the set of all ...
... and the third one is the canonical vector space identification. – By a straightforward coordinate calcultion we see that the brackets are also preserved. Example 3. Let V be a vector space of dimension n. Let End(V ) =the set of all linear maps from V to itself ∼ = M (n, R), Aut(V ) =the set of all ...
Products of Sums of Squares Lecture 1
... example, if there exists a composition formula of size [r, s, r ◦ s] then all three values are equal. Such constructions can be done whenever r is small: Lemma 9. If r ≤ 9 then r ∗ s = r # s = r ◦ s. Similarly 10 ◦ 10 = 16 and there is a normed [10, 10, 16], as we will see in Lecture 2. Therefore 10 ...
... example, if there exists a composition formula of size [r, s, r ◦ s] then all three values are equal. Such constructions can be done whenever r is small: Lemma 9. If r ≤ 9 then r ∗ s = r # s = r ◦ s. Similarly 10 ◦ 10 = 16 and there is a normed [10, 10, 16], as we will see in Lecture 2. Therefore 10 ...
Lie Groups and Their Lie Algebras One
... is a Lie group homomorphism. • In fact, as the next lemma shows, this is always the case, because every integral curve of X is defined for all time. Lemma 2. Every left-invariant vector field on a Lie group is complete. Proof. Let G be a Lie group, let X ∈ Lie(G), and let θ denote the flow of X. — S ...
... is a Lie group homomorphism. • In fact, as the next lemma shows, this is always the case, because every integral curve of X is defined for all time. Lemma 2. Every left-invariant vector field on a Lie group is complete. Proof. Let G be a Lie group, let X ∈ Lie(G), and let θ denote the flow of X. — S ...
Slide 1
... At first, a room is empty. Each minute, either one person enters or two people leave. After exactly 31999 minutes, could the room contain 31000 + 2 people? If there are n people in the room at a given time, there will be either n+3, n, n-3, or n-6 after 3 minutes. In other word, the increment is a m ...
... At first, a room is empty. Each minute, either one person enters or two people leave. After exactly 31999 minutes, could the room contain 31000 + 2 people? If there are n people in the room at a given time, there will be either n+3, n, n-3, or n-6 after 3 minutes. In other word, the increment is a m ...