Sebi Cioaba
I will post some math lectures and talks here. If you like any content, please let me know by subscribing, liking the videos and posting your comments.
Lecture 4 The char pol of the quotient matrix divides the graph char pol, friendship graph spectrum
Lecture 3 Equitable partitions, the eigenvalues of the quotient matrix are eigenvalues of the graph
Lecture 2 Equitable partitions, examples, quotient matrix, adjacency matrix
Lecture 1: Graphs, adjacency matrices, eigenvalues and eigenvectors, examples
39 Combinatorics Intro: Planar graphs, Dual graph, Euler's Formula v-e+f=2, 5 Color Theorem
38 Combinatorics Intro: Graph coloring, chromatic number, greedy coloring, Mycielski construction
37 Combinatorics Intro: Hungarian Algorithm, Tutte's Theorem, perfect matchings, Graph connectivity
36 Combinatorics Intro: Hall's Marriage Theorem, Birkhoff-von Neumann, Hungarian Algorithm
35 Combinatorics Intro: Hall's Marriage Theorem, bipartite regular graphs, Latin squares/rectangles
34 Combinatorics Intro: Matchings, Hall's Marriage Theorem, Systems of Distinct Representatives SDR
33 Combinatorics Intro: Eigenvalue Methods, Hoffman-Singleton theorem/graph, Sensitivity Conjecture
32 Combinatorics Intro: The degree-diameter problem, Moore bound, Hoffman-Singleton theorem
31 Combinatorics Intro: Diameter, the number of distinct eigenvalues, spectrum of bipartite graphs
30 Combinatorics Intro: Graphs, adjacency matrices, eigenvalues
29 Combinatorics Intro: Minimum weight spanning trees, Kruskal's algorithm, exchange property
28 Combinatorics Intro: Tree algorithms, breadth first search BFS, depth first search DFS
27 Combinatorics Intro: Kirchhoff Matrix-Tree theorem, proof, number of spanning trees
26 Combinatorics Intro: Laplacian matrix, incidence matrices, Kirchhoff Matrix-Tree theorem
25 Combinatorics Intro: Borchardt-Cayley theorem, Laplacian matrix, incidence matrices
24 Combinatorics Intro: trees, labeled vs unlabeled trees, Prufer codes
23 Combinatorics Intro: Konig theorem, trees
22 Combinatorics Intro: Euler-Hierholzer theorem, counting dominoes, Konig theorem
21 Combinatorics Intro: Havel-Hakimi theorem, Eulerian circuits, Euler-Hierholzer theorem
20 Combinatorics Intro: Degree sequences, graphic sequences, Havel-Hakimi theorem
19 Combinatorics Intro: Graphs, incidence matrices, degree sequences, graph isomorphism
18 Combinatorics Intro: Enumeration under group action III, Burnside's lemma
17 Combinatorics Intro: Enumeration under group action II, the class equation, Cauchy's theorem
16 Combinatorics Intro: Enumeration under group action I, Orbit-stabilizer lemma
15 Combinatorics Intro: Gaussian (q-binomial) coefficients vs (usual) binomial coefficients
14 Combinatorics Intro: Ferrers diagrams, Gaussian or q-binomial coefficients