1,543 research outputs found
Laplacian spectral characterization of some double starlike trees
A tree is called double starlike if it has exactly two vertices of degree
greater than two. Let denote the double starlike tree obtained by
attaching pendant vertices to one pendant vertex of the path and
pendant vertices to the other pendant vertex of . In this paper, we prove
that is determined by its Laplacian spectrum
The Weight Distributions of a Class of Cyclic Codes with Three Nonzeros over F3
Cyclic codes have efficient encoding and decoding algorithms. The decoding
error probability and the undetected error probability are usually bounded by
or given from the weight distributions of the codes. Most researches are about
the determination of the weight distributions of cyclic codes with few
nonzeros, by using quadratic form and exponential sum but limited to low
moments. In this paper, we focus on the application of higher moments of the
exponential sum to determine the weight distributions of a class of ternary
cyclic codes with three nonzeros, combining with not only quadratic form but
also MacWilliams' identities. Another application of this paper is to emphasize
the computer algebra system Magma for the investigation of the higher moments.
In the end, the result is verified by one example using Matlab.Comment: 10 pages, 3 table
Spectral characterizations of propeller graphs
A propeller graph is obtained from an -graph by attaching a path to
the vertex of degree four, where an -graph consists of two cycles with
precisely one common vertex. In this paper, we prove that all propeller graphs
are determined by their Laplacian spectra as well as their signless Laplacian
spectra
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