M. Kannan

activity

20142026

most citedOn weakly irreducible nonnegative tensors and interval hull of some classes of tensors

10 citations · 39 across the 21 of their papers we have counts for

collaborators

27 papers

math.CO2026

Localized Turán-type inequalities for $Q$ -index

M. Rajesh Kannan, Hitesh Kumar, Shivaramakrishna Pragada

For a connected graph $G$, let $q (G)$ denote the $Q$ -index of $G$ , i.e., the largest eigenvalue of its signless Laplacian matrix. Abreu and Nikiforov (2013) showed that \[ q(G) \…

math.CO2023

Bounds and extremal graphs for the energy of complex unit gain graphs

Aniruddha Samanta, M. Rajesh Kannan

A complex unit gain graph ( $T$ -gain graph), $Φ = (G, φ)$ is a graph where the gain function $φ$ assigns a unit complex number to each orientation of an edge of $G$ an…

math.CO2023

A note on the distance and distance signless Laplacian spectral radius of complements of trees

Iswar Mahato, M. Rajesh Kannan

In this article, we show that the generalized tree shift operation increases the distance spectral radius, distance signless Laplacian spectral radius, and the $D_{α}$ -spectral radiu…

math.CO2023

Extremal problems for the eccentricity matrices of complements of trees

Iswar Mahato, M. Rajesh Kannan

The eccentricity matrix of a connected graph $G$ , denoted by $E (G)$ , is obtained from the distance matrix of $G$ by keeping the largest nonzero entries in each row and ea…

math.CO2022★ 1 cited

Minimizers for the energy of eccentricity matrices of trees

Iswar Mahato, M. Rajesh Kannan

The eccentricity matrix of a connected graph $G$ , denoted by $E (G)$ , is obtained from the distance matrix of $G$ by keeping the largest nonzero entries in each row and ea…

math.CO2022★ 1 cited

Squared distance matrices of trees with matrix weights

Iswar Mahato, M. Rajesh Kannan

Let $T$ be a tree on $n$ vertices whose edge weights are positive definite matrices of order $s$ . The squared distance matrix of $T$ , denoted by $Δ$ , is the $n s \times n s$ block ma…

math.CO2022

Signed spectral Turań type theorems

M. Rajesh Kannan, Shivaramakrishna Pragada

A signed graph $Σ = (G, σ)$ is a graph where the function $σ$ assigns either $1$ or $- 1$ to each edge of the simple graph $G$ . The adjacency matrix of $Σ$ , denoted by $A (Σ)$ , is def…

math.CO2022★ 3 cited

On the eccentricity matrices of trees: Inertia and spectral symmetry

Iswar Mahato, M. Rajesh Kannan

The \textit{eccentricity matrix} $E (G)$ of a connected graph $G$ is obtained from the distance matrix of $G$ by keeping the largest non-zero entries in each row and each…

math.CO2021★ 5 cited

On the construction of cospectral nonisomorphic bipartite graphs

M. Rajesh Kannan, Shivaramakrishna Pragada, Hitesh Wankhede

In this article, we construct bipartite graphs which are cospectral for both the adjacency and normalized Laplacian matrices using partitioned tensor product. This extends the cons…

math.CO2021

Eccentricity energy change of complete multipartite graphs due to edge deletion

Iswar Mahato, M. Rajesh Kannan

The eccentricity matrix $ε (G)$ of a graph $G$ is obtained from the distance matrix of $G$ by retaining the largest distances in each row and each column, and leaving zero…

math.CO2021

Bounds for the extremal eigenvalues of gain Laplacian matrices

M. Rajesh Kannan, Navish Kumar, Shivaramakrishna Pragada

A complex unit gain graph ( $T$ -gain graph), $Φ = (G, φ)$ is a graph where the function $φ$ assigns a unit complex number to each orientation of an edge of $G$ , and its inve…

math.CO2021

Gain distance matrices for complex unit gain graphs

Aniruddha Samanta, M. Rajesh Kannan

A complex unit gain graph ( $T$ -gain graph), $Φ = (G, φ)$ is a graph where the function $φ$ assigns a unit complex number to each orientation of an edge of $G$ , and it…

math.CO2021

On the multiplicity of $A α$ -eigenvalues and the rank of complex unit gain graphs

Aniruddha Samanta, M. Rajesh Kannan

Let $Φ = (G, φ)$ be a connected complex unit gain graph ( $T$ -gain graph) on a simple graph $G$ with $n$ vertices and maximum vertex degree $Δ$ . The associated adjac…

math.RA2020

Interval hulls of $N$ -matrices and almost $P$ -matrices

Projesh Nath Choudhury, M. Rajesh Kannan

We establish a characterization of almost $P$ -matrices via a sign non-reversal property. In this we are inspired by the analogous results for $N$ -matrices. Next, the interval hull…

math.CO2020

Normalized Laplacians for Gain Graphs

M. Rajesh Kannan, Navish Kumar, Shivaramakrishna Pragada

We propose the notion of normalized Laplacian matrix $L (Φ)$ for a gain graphs and study its properties in detail, providing insights and counterexamples along the way. We…

math.CO2020

On the $A_{α}$ -spectra of some join graphs

Mainak Basunia, Iswar Mahato, M. Rajesh Kannan

Let $G$ be a simple, connected graph and let $A (G)$ be the adjacency matrix of $G$ . If $D (G)$ is the diagonal matrix of the vertex degrees of $G$ , then for every real $α \in [0, 1]$ ,…

math.RA2020★ 7 cited

Sign non-reversal property for totally non-negative and totally positive matrices, and testing total positivity of their interval hull

Projesh Nath Choudhury, M. Rajesh Kannan, Apoorva Khare

A matrix $A$ is totally positive (or non-negative) of order $k$ , denoted $T P_{k}$ (or $T N_{k}$ ), if all minors of size $\leq k$ are positive (or non-negative). It is well-known that su…

math.FA2020

Bounds for a solution set of linear complementarity problems over Hilbert spaces

Projesh Nath Choudhury, M. Rajesh Kannan, K. C. Sivakumar

Let $H$ be a real Hilbert space. In this short note, using some of the properties of bounded linear operators with closed range defined on $H$ , certain bounds for a specific convex…

math.CO2020

Bounds for the energy of a complex unit gain graph

Aniruddha Samanta, M. Rajesh Kannan

A $T$ -gain graph, $Φ = (G, φ)$ , is a graph in which the function $φ$ assigns a unit complex number to each orientation of an edge, and its inverse is assigned to the opposi…

math.FA2020

On dense subsets of matrices with distinct eigenvalues and distinct singular values

Himadri Lal Das, M. Rajesh Kannan

It is well known that the set of all $n \times n$ matrices with distinct eigenvalues is a dense subset of the set of all real or complex $n \times n$ matrices. In [Hartfiel, D.…

math.CO2020

On the construction of cospectral graphs for the adjacency and normalized Laplacian matrices

M. Rajesh Kannan, Shivaramakrishna Pragada

In [Steve Butler. A note about cospectral graphs for the adjacency and normalized Laplacian matrices. Linear Multilinear Algebra, 58(3-4):387-390, 2010.], Butler constructed a fami…

math.CO2019★ 6 cited

On the spectral radius and the energy of eccentricity matrix of a graph

Iswar Mahato, R. Gurusamy, M. Rajesh Kannan +1

The eccentricity matrix $ε (G)$ of a graph $G$ is obtained from the distance matrix by retaining the eccentricities (the largest distance) in each row and each column. In…

math.CO2019★ 6 cited

On the spectrum of complex unit gain graph

Aniruddha Samanta, M. Rajesh Kannan

A $T$ -gain graph is a simple graph in which a unit complex number is assigned to each orientation of an edge, and its inverse is assigned to the opposite orientation. The…

math.CO2018

Eigenvalue bounds for some classes of matrices associated with graphs

Ranjit Mehatari, M. Rajesh Kannan

For a given complex square matrix $A$ with constant row sum, we establish two new eigenvalue inclusion sets. Using these bounds, first we derive bounds for the second largest and s…

Localized Turán-type inequalities for Q-index

Bounds and extremal graphs for the energy of complex unit gain graphs

A note on the distance and distance signless Laplacian spectral radius of complements of trees

Extremal problems for the eccentricity matrices of complements of trees

Minimizers for the energy of eccentricity matrices of trees

Squared distance matrices of trees with matrix weights

Signed spectral Turań type theorems

On the eccentricity matrices of trees: Inertia and spectral symmetry

On the construction of cospectral nonisomorphic bipartite graphs

Eccentricity energy change of complete multipartite graphs due to edge deletion

Bounds for the extremal eigenvalues of gain Laplacian matrices

Gain distance matrices for complex unit gain graphs

On the multiplicity of Aα-eigenvalues and the rank of complex unit gain graphs

Interval hulls of N-matrices and almost P-matrices

Normalized Laplacians for Gain Graphs

On the Aα​-spectra of some join graphs

Sign non-reversal property for totally non-negative and totally positive matrices, and testing total positivity of their interval hull

Bounds for a solution set of linear complementarity problems over Hilbert spaces

Bounds for the energy of a complex unit gain graph

On dense subsets of matrices with distinct eigenvalues and distinct singular values

On the construction of cospectral graphs for the adjacency and normalized Laplacian matrices

On the spectral radius and the energy of eccentricity matrix of a graph

On the spectrum of complex unit gain graph

Eigenvalue bounds for some classes of matrices associated with graphs

Localized Turán-type inequalities for $Q$ -index

On the multiplicity of $A α$ -eigenvalues and the rank of complex unit gain graphs

Interval hulls of $N$ -matrices and almost $P$ -matrices

On the $A_{α}$ -spectra of some join graphs