Flashcards
Groups
Flashcards do conjunto (67)
- 1Definition of a groupPage 2
- 2Proof of other group properties from definitionPage 3
- 3Subgroup criterion + proofPage 5
- 4Subgroups of (Z, +, 0) are precisely the subsets nZPage 5
- 5D_2n is a group with 2n elementsPage 6
- 6Definition of homomorphism and proof of basic propertiesPage 8
- 7Definition of image and kernel of homomorphismPage 8
- 8Image and Kernel are subgroups in respective groupsPage 8
- 9Injectivity of homomorphism condition and proofPage 9
- 10A cyclic group is isomorphic to some Cn or (Z, +, 0)Page 9
- 11Mobius group definition and proof of group structurePage 11
- 12Every Mobius transformation is a composition of z+b, az and 1/z (in fact only two of these - prove)Page 12/ example sheet
- 13*Mobius transformation with >= 3 fixed points is identityPage 13
- 14*There is a unique mobius transformation mapping any 3 distinct complex numbers to and 3 distinct complex numbersPage 13
- 15Conjugacy is an equivalence relationPage 14
- 16*Any non-identity Mobius transformation has 1 or 2 fixed points (what are they conjugate to?)Page 14
- 17Definition of a 'circle' in CPage 14
- 18Mobius transformations send 'circles' to 'circles'Page 15
- 19An invertible function preserves cross ratios iff it is a Mobius transformationPage 15
- 20Condition for 4 points to lie on a circle in C, based on cross ratioPage 15
- 21Action definition (left and right)Page 16
- 22Action is equivalent to a homomorphismPage 16
- 23Cayley's theoremPage 17
- 24Definitions of orbit, stabiliser, kernel, transitive, faithful with regard to group actionsPage 17
- 25Stabiliser is a subgroup, orbits partition XPage 17
- 26Set of orbits notation for left and right actionsPage 18
- 27Regular actionPage 19
- 28Coset definitionPage 19
- 29Lagrange's TheoremPage 20
- 30Fermat-Euler TheoremPage 21
- 31*Orbit-Stabiliser TheoremPage 22
- 32*Cauchy's TheoremPage 23
- 33Conjugation action and associated terminologyPage 24
- 34Conjugation of a subgroup produces another subgroup (i.e. G acts on its subgroups by conjugation)Page 24
- 35Natural bijection between left and right cosetsExample sheet
- 36Quaternion matricesPage 25
- 37Chinese Remainder TheoremPage 25
- 38Direct product theoremPage 26
- 39*Classification of groups up to size 8 (and size 2p)Page 27 (and example sheet)
- 40Normal subgroup iff gH=Hg for all gPage 29
- 41Subgroup is normal iff it is the kernel of some homomorphismPage 29 and example sheet
- 42*Isomorphism theoremPage 31
- 43Use a tetrahedron to show that S4/K is isomorphic to S3 for some normal subgroup KPage 33
- 44Difference between Sn and Sym(X)Page 33
- 45Disjoint cycles commute and every permutation can be 'uniquely' written as a composition of disjoint cycles in which each 1 - n appears exactly oncePage 35
- 46Order of a permutationPage 35
- 47Every permutation is a product of transpositionsPage 36
- 48Sign of a permutation is a well-defined homomorphismPage 36
- 49Conjuagation and conjugacy classes in SnPage 37
- 50Size of stabilisers and conjugacy classes in SnPage 38
- 51Conjugation and conjugacy classes in AnPage 40
- 52A5 is simplePage 41
- 53Definitions of common matrix groupsPage 42
- 54How does GLn act on Mnxn ?Page 42
- 55Jordan Normal FormPage 43
- 56Homomorphism from SL2(C) to M is surjective with Kernel + or - IPage 44
- 57Projective Special Linear GroupPage 45
- 58*A matrix is in O(n) iff it preserves dot productPage 46
- 59Reflections and proof that Ra is in O(n)Page 46
- 60Conjugation of reflectionPage 47
- 61Every element of O(n) is a rotation or reflectionPage 48
- 62Every element of O(2) is a composition of at most 2 reflectionsPage 49
- 63For every A in SO(3) there is a unit vector v such that Av=vPage 49
- 64Every matrix in SO(3) is a rotationPage 49
- 65Every matrix in O(3) is a composition of at most 3 reflectionsPage 50
- 66Every group of order p^2 is abelianExample sheet 2
- 67Show that if a normal subgroup N of O(2) contains a reflection that N = O(2)Example sheet 4
Informações
- Descrição
- Part 1A FlashCards sobre Groups, criado por Melissa Quail em 09-01-2019.
- Criado por
- Melissa Quail
- Visualizações
- 40
- Avaliação