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Some graphs determined by their (signless) Laplacian spectra

Muhuo Liu (2012)

Czechoslovak Mathematical Journal

Let W n = K 1 C n - 1 be the wheel graph on n vertices, and let S ( n , c , k ) be the graph on n vertices obtained by attaching n - 2 c - 2 k - 1 pendant edges together with k hanging paths of length two at vertex v 0 , where v 0 is the unique common vertex of c triangles. In this paper we show that S ( n , c , k ) ( c 1 , k 1 ) and W n are determined by their signless Laplacian spectra, respectively. Moreover, we also prove that S ( n , c , k ) and its complement graph are determined by their Laplacian spectra, respectively, for c 0 and k 1 .

Some inequalities involving upper bounds for some matrix operators. I

R. Lashkaripour, D. Foroutannia (2007)

Czechoslovak Mathematical Journal

In this paper we consider the problem of finding upper bounds of certain matrix operators such as Hausdorff, Nörlund matrix, weighted mean and summability on sequence spaces l p ( w ) and Lorentz sequence spaces d ( w , p ) , which was recently considered in [9] and [10] and similarly to [14] by Josip Pecaric, Ivan Peric and Rajko Roki. Also, this study is an extension of some works by G. Bennett on l p spaces, see [1] and [2].

Some new bounds of the minimum eigenvalue for the Hadamard product of anM-matrix and an inverseM-matrix

Jianxing Zhao, Caili Sang (2016)

Open Mathematics

Some convergent sequences of the lower bounds of the minimum eigenvalue for the Hadamard product of a nonsingular M-matrix B and the inverse of a nonsingular M-matrix A are given by using Brauer’s theorem. It is proved that these sequences are monotone increasing, and numerical examples are given to show that these sequences could reach the true value of the minimum eigenvalue in some cases. These results in this paper improve some known results.

Some norm inequalities for special Gram matrices

Ramazan Türkmen, Osman Kan, Hasan Gökbas (2016)

Special Matrices

In this paper we firstly give majorization relations between the vectors Fn = {f0, f1, . . . , fn−1},Ln = {l0, l1, . . . , ln−1} and Pn = {p0, p1, . . . , pn−1} which constructed with fibonacci, lucas and pell numbers. Then we give upper and lower bounds for determinants, Euclidean norms and Spectral norms of Gram matrices GF=〈Fn,Fni〉, GL=〈Ln,Lni〉, GP=〈Pn,Pni〉, GFL=〈Fn,Lni〉, GFP=〈Fn,Pni〉.

Some partial differential equations in Clifford analysis

Elena Obolashvili (1996)

Banach Center Publications

Using Clifford analysis in a multidimensional space some elliptic, hyperbolic and parabolic systems of partial differential equations are constructed, which are related to the well-known classical equations. To obtain parabolic systems Clifford algebra is modified and some corresponding differential operator is constructed. For systems obtained the boundary and initial value problems are solved.

Some properties complementary to Brualdi-Li matrices

Chuanlong Wang, Xuerong Yong (2015)

Czechoslovak Mathematical Journal

In this paper we derive new properties complementary to an 2 n × 2 n Brualdi-Li tournament matrix B 2 n . We show that B 2 n has exactly one positive real eigenvalue and one negative real eigenvalue and, as a by-product, reprove that every Brualdi-Li matrix has distinct eigenvalues. We then bound the partial sums of the real parts and the imaginary parts of its eigenvalues. The inverse of B 2 n is also determined. Related results obtained in previous articles are proven to be corollaries.

Some properties of generalized distance eigenvalues of graphs

Yuzheng Ma, Yan Ling Shao (2024)

Czechoslovak Mathematical Journal

Let G be a simple connected graph with vertex set V ( G ) = { v 1 , v 2 , , v n } and edge set E ( G ) , and let d v i be the degree of the vertex v i . Let D ( G ) be the distance matrix and let T r ( G ) be the diagonal matrix of the vertex transmissions of G . The generalized distance matrix of G is defined as D α ( G ) = α T r ( G ) + ( 1 - α ) D ( G ) , where 0 α 1 . Let λ 1 ( D α ( G ) ) λ 2 ( D α ( G ) ) ... λ n ( D α ( G ) ) be the generalized distance eigenvalues of G , and let k be an integer with 1 k n . We denote by S k ( D α ( G ) ) = λ 1 ( D α ( G ) ) + λ 2 ( D α ( G ) ) + ... + λ k ( D α ( G ) ) the sum of the k largest generalized distance eigenvalues. The generalized distance spread of a graph G is defined as D α S ( G ) = λ 1 ( D α ( G ) ) - λ n ( D α ( G ) ) . We obtain some...

Some Properties of Mittag-Leffler Functions and Matrix-Variate Analogues: A Statistical Perspective

Mathai, A. (2010)

Fractional Calculus and Applied Analysis

Mathematical Subject Classification 2010:26A33, 33E99, 15A52, 62E15.Mittag-Leffler functions and their generalizations appear in a large variety of problems in different areas. When we move from total differential equations to fractional equations Mittag-Leffler functions come in naturally. Fractional reaction-diffusion problems in physical sciences and general input-output models in other disciplines are some of the examples in this direction. Some basic properties of Mittag-Leffler functions are...

Some properties of N-supercyclic operators

P. S. Bourdon, N. S. Feldman, J. H. Shapiro (2004)

Studia Mathematica

Let T be a continuous linear operator on a Hausdorff topological vector space 𝓧 over the field ℂ. We show that if T is N-supercyclic, i.e., if 𝓧 has an N-dimensional subspace whose orbit under T is dense in 𝓧, then T* has at most N eigenvalues (counting geometric multiplicity). We then show that N-supercyclicity cannot occur nontrivially in the finite-dimensional setting: the orbit of an N-dimensional subspace cannot be dense in an (N+1)-dimensional space. Finally, we show that a subnormal operator...

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