Taking a Fiedler’s result [1] on the spectrum of a matrix formed from two symmetric matrices as a motivation, a more general result is deduced and applied to the determination of adjacency and Laplacian spectra of graphs obtained by a generalized join graph operation on families of graphs (regular in the case of adjacency spectra and arbitrary in the case of Laplacian spectra). Some additional ...

A molecular similarity measure has been developed using molecular topological graphs and atomic partial charges. Two kinds of topological graphs were used. One is the ordinary adjacency matrix and the other is a matrix which represents the minimum path length between two atoms of the molecule. The ordinary adjacency matrix is suitable to compare the local structures of molecules such as functio...

The method of permutation decoding was first developed by MacWilliams in the early 60’s and can be used when a linear code has a sufficiently large automorphism group to ensure the existence of a set of automorphisms, called a PD-set, that has some specifed properties. These talks will describe some recent developments in finding PD-sets for codes defined through the row-span over finite fields...

Any directed graph G with N vertices and J edges has an associated line-graph L(G) where the J edges form the vertices of L(G). We show that the non-zero eigenvalues of the adjacency matrices are the same for all graphs of such a family Ln(G). We give necessary and sufficient conditions for a line-graph to be quantisable and demonstrate that the spectra of associated quantum propagators follow ...

We propose a novel variational method for solving the sub-graph isomorphism problem on gate-based quantum computer. The relies (1) new representation of adjacency matrices underlying graphs, which requires number qubits that scales logarithmically with vertices graphs; and (2) ansatz can efficiently probe permutation space. Simulations are then presented to showcase approach graphs up 16 vertic...

We consider a probabilistic construction of sparse random matrices where each column has a fixed number of nonzeros whose row indices are drawn uniformly at random. These matrices have a one-to-one correspondence with the adjacency matrices of lossless expander graphs. We present tail bounds on the probability that the cardinality of the set of neighbors for these graphs will be less than the e...

Given a perfect coloring of graph, we prove that the $L_1$ distance between two rows adjacency matrix graph is not less than corresponding parameter coloring. With help an algebraic approach, deduce corollaries this result for $2$-colorings, colorings in distance-$l$ graphs and distance-regular graphs. We also provide examples when obtained property reject several putative matrices infinite

We revisit the probabilistic construction of sparse random matrices where each column has a fixed number of nonzeros whose row indices are drawn uniformly at random. These matrices have a one-to-one correspondence with the adjacency matrices of lossless expander graphs. We present tail bounds on the probability that the cardinality of the set of neighbors for these graphs will be less than the ...

We construct qubit stabilizer codes with parameters 〚 81 , 0 20 〛 2 and 94 22 for the first time. use symplectic self-dual additive over F 4 built by modifying adjacency matrices of suitable metacirculant graphs found a randomized search procedure.