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Durmuş Bozkurt

Publications and source records attributed to Durmuş Bozkurt.

17 recordsLinked to original sources
arXiv2014

Note on the Sum of Powers of Signless Laplacian Eigenvalues of Graphs

For a simple graph $G$ and a real number $α$ $\left(α\neq 0,1\right) $ the graph invariant $s_α\left(G\right) $ is equal to the sum of powers of signless Laplacian eigenvalues of $G$. In this note, we present some new bounds on $s_α\left(G\right) $. As a result of these bounds, we also give some results on incidence energy.

math.CO↗
arXiv2012

Bounds For The Distance Estrada Index Of Graphs

The D-eigenvalues μ_1,μ_2,...,μ_{n} of a connected graph G are the eigenvalues of its distance matrix. The distance Estrada index of G is defined in [15] as DEE=DEE(G)=Σ_{i=1}^n e^{μ_{i}} In this paper, we give better lower bounds for the distance Estrada index of any connected graph as well as some relations between DEE(G) and the distance energy.

math.CO↗
arXiv2012

The adjacency matrix of one type of graph and the Fibonacci numbers

Recently there is huge interest in graph theory and intensive study on computing integer powers of matrices. In this paper, we investigate relationships between one type of graph and well-known Fibonacci sequence. In this content, we consider the adjacency matrix of one type of graph with 2k (k=1,2,...) vertices. It is also known that for any positive integer r, the (i,j)th entry of A^{r} (A is the adjacency matrix of the graph) is just the number of walks from vertex i to vertex j, that use exactly k edges.

math.NT↗
arXiv2012

On the Determinants and Inverses of Circulant Matrices with a General Number Sequence

The generalized sequence of numbers is defined by W_{n}=pW_{n-1}+qW_{n-2} with initial conditions W_{0}=a and W_{1}=b for a,b,p,q\inZ and n\geq2, respectively. Let W_{n}=circ(W_{1},W_{2},...,W_{n}). The aim of this paper is to establish some useful formulas for the determinants and inverses of W_{n} using the nice properties of the number sequences. Matrix decompositions are derived for W_{n} in order to obtain the results.

math.NA↗
arXiv2012

Determinants and Inverses of Circulant Matrices with Jacobsthal and Jacobsthal-Lucas Numbers

Let n\geq3 and J_{n}:=circ(J_{1},J_{2},...,J_{n}) and j_{n}:=\circ(j_{0},j_{1},...,j_{n-1}) be the n\timesn circulant matrices, associated with the nth Jacobsthal number J_{n} and the nth Jacobsthal-Lucas number j_{n}, respectively. The determinants of J_{n} and j_{n} are obtained in terms of the Jacobsthal and Jacobsthal-Lucas numbers. These imply that J_{n} and j_{n} are invertible. We also derive the inverses of J_{n} and j_{n}.

math.NA↗
arXiv2012

On the Determinants and Inverses of Circulant Matrices with Pell and Pell-Lucas Numbers

Let P=\circ(P_{1},P_{2},...,P_{n}) and Q=\circ(Q_{1},Q_{2},...,Q_{n}) be n\timesn circulant matrices where P_{n} and Q_{n} are nth Pell and Pell-Lucas numbers, respectively. The determinants of the matrices P and Q were expressed by the Pell and Pell-Lucas numbers. After, we prove that the matrices P and Q are the invertible for n\geq3 and then the inverses of the matrices P and Q are derived.

math.NA↗
arXiv2011

An Inversion Algorithm for Cyclic Nonadiagonal Matrix

In this paper, we compose a computational algorithm for the determinant and the inverse of the n x n cyclic nonadiagonal matrix. The algorithm is suited for implementation using computer algebra systems (CAS) such as Mathematica and Maple.

math.NA↗
arXiv2011

A New Algorithm for the Inverse of Periodic k Banded and Periodic Anti k banded Matrices

In this study, an algorithm for computing the inverse of periodic k banded matrices, which are needed for solving the differential equations by using the finite differences, the solution of partial differential equations and the solution of boundary value problems is obtained and the inverses of periodic anti k banded matrices are computed. In addition, the determinant of these type of matrices and the solution of linear systems having these coefficient matrices are investigated. When obtaining this algorithm, the LU factorization is used.The algorithm is implementable to the CAS (Computer Algebra Systems) such as Maple and Mathematica.

math.SP↗