Page 21 - 8th European Congress of Mathematics ∙ 20-26 June 2021 ∙ Portorož, Slovenia ∙ Book of Abstracts
P. 21
CONTENTS
Mimi Zhang: Trivalent dihedrants and bi-dihedrants . . . . . . . . . . . . . . . . . . . 318
Jinxin Zhou: Symmetries of bi-Cayley graphs . . . . . . . . . . . . . . . . . . . . . . . 319
Sanming Zhou: Perfect 2-colourings of Cayley graphs . . . . . . . . . . . . . . . . . . 319
Spectral Graph Theory (MS-46) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Maurizio Brunetti: Playing with quaternions unit gain graphs . . . . . . . . . . . . . . 322
Paula Carvalho: Complementary prisms and their spectra . . . . . . . . . . . . . . . . . 322
Cristina Dalfo: Spectra and eigenspaces from regular partitions of Cayley (di)graphs of
permutation groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Alexander Farrugia: On the rank of pseudo walk matrices . . . . . . . . . . . . . . . . 322
Miquel Àngel Fiol Mora: The local spectra of a graph and some of their applications . . . 323
Gary Greaves: Maximal cliques in strongly regular graphs . . . . . . . . . . . . . . . . 323
Clemens Huemer: Optimal Grid Drawings of Complete Multipartite Graphs and an Integer
Variant of the Algebraic Connectivity . . . . . . . . . . . . . . . . . . . . . . . . . 324
Ivana Jovovic´: Strongly regular signed graphs and association schemes . . . . . . . . . . 324
Tamara Koledin: Classes of strongly regular signed graphs . . . . . . . . . . . . . . . . 324
Jack Koolen: Systems of equiangular lines, Seidel matrices and adjacency matrices . . . . 325
Fernando Lledó: Isospectral magnetic graphs . . . . . . . . . . . . . . . . . . . . . . 325
Ignacio Lopez Lorenzo: Almost mixed Moore graphs and their spectra . . . . . . . . . . 326
Berenice Martínez Barona: Characterizing identifying codes from the spectrum of a graph
or digraph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Bojana Mihailovic´: On some classes of signed graphs with small second largest eigenvalue 326
Suil O: Eigenvalues and [a, b]-factors in regular graphs . . . . . . . . . . . . . . . . . . 327
Sonˇa Pavlíková: Construction of upper bounds of the HOMO-LUMO spectral gaps by
semidefinite relaxation techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Safet Penjic´: On symmetric association schemes and associated quotient-polynomial graphs 328
Symmetry of Graphs, Maps and Polytopes (MS-9) . . . . . . . . . . . . . . . . . . . 329
Marston Conder: Some observations about regular maps . . . . . . . . . . . . . . . . . 330
Wilfried Imrich: On the Asymmetrizing Cost and Density of Graphs . . . . . . . . . . . . 330
Robert Jajcay: Non-Cayley regular maps and generalizations of skew-morphisms . . . . . 331
Gareth A. Jones: Realisation of groups as automorphism groups of maps and hypermaps . 331
Boštjan Kuzman: On rainbow domination in regular and symmetric graphs . . . . . . . . 332
Luis Martínez: Cyclotomic Association Schemes of Broad Classes and Applications to the
Construction of Combinatorial Structures . . . . . . . . . . . . . . . . . . . . . . . 332
Dragan Marušicˇ: Intersection densities of transitive permutation groups . . . . . . . . . . 333
Dave Witte Morris: On automorphisms of direct products of abelian Cayley graphs . . . . 333
Joy Morris: Base sizes for the symmetric and alternating groups . . . . . . . . . . . . . . 333
Marko Orel: A family of non-Cayley cores that are constructed from vertex-transitive or
strongly regular self-complementary graphs . . . . . . . . . . . . . . . . . . . . . . 334
Cheryl Praeger: Having fun with designs . . . . . . . . . . . . . . . . . . . . . . . . . 334
Olivia Reade: Edge-biregular maps . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
Alan Reid: Distinguishing discrete groups by their finite quotients . . . . . . . . . . . . . 335
Sebastián Reyes-Carocca: On compact Riemann surfaces and hypermaps of genus p + 1
where p is prime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
Egon Schulte: Geometry and Combinatorics of Semiregular Polytopes . . . . . . . . . . . 335
Jozef Širánˇ: Regular and ‘half-regular’ maps of negative prime Euler characteristic . . . . 336
Asia Ivic´ Weiss: Proper locally spherical hypertopes of hyperbolic type . . . . . . . . . . 337
19
Mimi Zhang: Trivalent dihedrants and bi-dihedrants . . . . . . . . . . . . . . . . . . . 318
Jinxin Zhou: Symmetries of bi-Cayley graphs . . . . . . . . . . . . . . . . . . . . . . . 319
Sanming Zhou: Perfect 2-colourings of Cayley graphs . . . . . . . . . . . . . . . . . . 319
Spectral Graph Theory (MS-46) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Maurizio Brunetti: Playing with quaternions unit gain graphs . . . . . . . . . . . . . . 322
Paula Carvalho: Complementary prisms and their spectra . . . . . . . . . . . . . . . . . 322
Cristina Dalfo: Spectra and eigenspaces from regular partitions of Cayley (di)graphs of
permutation groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Alexander Farrugia: On the rank of pseudo walk matrices . . . . . . . . . . . . . . . . 322
Miquel Àngel Fiol Mora: The local spectra of a graph and some of their applications . . . 323
Gary Greaves: Maximal cliques in strongly regular graphs . . . . . . . . . . . . . . . . 323
Clemens Huemer: Optimal Grid Drawings of Complete Multipartite Graphs and an Integer
Variant of the Algebraic Connectivity . . . . . . . . . . . . . . . . . . . . . . . . . 324
Ivana Jovovic´: Strongly regular signed graphs and association schemes . . . . . . . . . . 324
Tamara Koledin: Classes of strongly regular signed graphs . . . . . . . . . . . . . . . . 324
Jack Koolen: Systems of equiangular lines, Seidel matrices and adjacency matrices . . . . 325
Fernando Lledó: Isospectral magnetic graphs . . . . . . . . . . . . . . . . . . . . . . 325
Ignacio Lopez Lorenzo: Almost mixed Moore graphs and their spectra . . . . . . . . . . 326
Berenice Martínez Barona: Characterizing identifying codes from the spectrum of a graph
or digraph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Bojana Mihailovic´: On some classes of signed graphs with small second largest eigenvalue 326
Suil O: Eigenvalues and [a, b]-factors in regular graphs . . . . . . . . . . . . . . . . . . 327
Sonˇa Pavlíková: Construction of upper bounds of the HOMO-LUMO spectral gaps by
semidefinite relaxation techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Safet Penjic´: On symmetric association schemes and associated quotient-polynomial graphs 328
Symmetry of Graphs, Maps and Polytopes (MS-9) . . . . . . . . . . . . . . . . . . . 329
Marston Conder: Some observations about regular maps . . . . . . . . . . . . . . . . . 330
Wilfried Imrich: On the Asymmetrizing Cost and Density of Graphs . . . . . . . . . . . . 330
Robert Jajcay: Non-Cayley regular maps and generalizations of skew-morphisms . . . . . 331
Gareth A. Jones: Realisation of groups as automorphism groups of maps and hypermaps . 331
Boštjan Kuzman: On rainbow domination in regular and symmetric graphs . . . . . . . . 332
Luis Martínez: Cyclotomic Association Schemes of Broad Classes and Applications to the
Construction of Combinatorial Structures . . . . . . . . . . . . . . . . . . . . . . . 332
Dragan Marušicˇ: Intersection densities of transitive permutation groups . . . . . . . . . . 333
Dave Witte Morris: On automorphisms of direct products of abelian Cayley graphs . . . . 333
Joy Morris: Base sizes for the symmetric and alternating groups . . . . . . . . . . . . . . 333
Marko Orel: A family of non-Cayley cores that are constructed from vertex-transitive or
strongly regular self-complementary graphs . . . . . . . . . . . . . . . . . . . . . . 334
Cheryl Praeger: Having fun with designs . . . . . . . . . . . . . . . . . . . . . . . . . 334
Olivia Reade: Edge-biregular maps . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
Alan Reid: Distinguishing discrete groups by their finite quotients . . . . . . . . . . . . . 335
Sebastián Reyes-Carocca: On compact Riemann surfaces and hypermaps of genus p + 1
where p is prime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
Egon Schulte: Geometry and Combinatorics of Semiregular Polytopes . . . . . . . . . . . 335
Jozef Širánˇ: Regular and ‘half-regular’ maps of negative prime Euler characteristic . . . . 336
Asia Ivic´ Weiss: Proper locally spherical hypertopes of hyperbolic type . . . . . . . . . . 337
19
