000 02617n a2200301#a 4500
001 40075
003 P5A
005 20230123132000.0
007 cr cuuuuuauuuu
008 210614s2021 bl por d
035 _aocm51338542
040 _aP5A
_cP5A
090 _atimpa
100 1 _aMattos, Letícia Dias
_91184
245 1 0 _aCombinatorial properties of random graphs and matrices/
_cLetícia Dias Mattos.
246 1 1 _aPropriedades combinatoriais de matrizes e gráficos aleatórios
260 _aRio de Janeiro:
_bIMPA,
_c2021.
300 _avideo online
500 _aDefesa de Tese.
500 _aBanca examinadora: Robert Morris (IMPA, orientador) Roberto Imbuzeiro Oliveira (IMPA) Maurício Collares (UFMG) Taísa Martins (UFF) Guilherme Oliveira Mota (USP) Suplente: Simon Griffiths (PUC-Rio)
505 1 _aAbstract: In this thesis we study two of the main objects in probabilistic combinatorics: random matrices and random graphs. In the first part, joint with Campos, Morris and Morrison, we consider a uniformly-chosen random symmetric matrix with entries in {-1,+1}. We obtain an ‘exponential-type’ bound on the probability that this matrix is singular. Our main new ingredient is an inverse Littlewood--Offord theorem whose statement is inspired by the method of hypergraph containers. In the second part, joint with Griffiths and Morris, we study the size of the maximum k-clique packing in the random graph G(n,p). A clique packing is just a set of edge-disjoint cliques. For every value of k which is close to the size of the largest clique in G(n,p), we obtain the order of the maximum k-clique packing in G(n,p). To show this result, we follow a random greedy process and use the differential equation method. In the third part, joint with Liebenau, Mendonça and Skokan, we study asymmetric Ramsey properties of G(n,p) for cliques and cycles. For any pair of r-clique and k-cycle, we determine the threshold for finding a red copy of a r-clique or a blue copy of a k-cycle in every red and blue edge-colouring of G(n,p). The main tool behind the proof is a structural characterisation of Ramsey graphs for each pair of r-clique and k-cycle .
650 0 4 _aMatematica.
_2larpcal
_919899
697 _aTeses do IMPA
_924311
700 1 _aMorris, Robert,
_u(IMPA)
_eorientador
_9974
711 2 _aDefesa de Tese
_910070
856 4 _zVIDEO
_uhttps://bit.ly/2TnAVEI
942 _2impa
_cVIDEO
999 _aCOMBINATORIAL properties of random graphs and matrices. Letícia Dias Mattos. Rio de Janeiro: IMPA, 2021. video online. Disponível em: <https://bit.ly/2TnAVEI>. Acesso em: 14 jun. 2021.
_c38717
_d38717