Radha Ramakrishnan

activity

20212026

collaborators

8 papers

math.CA2026

Frames and Bases of Translates of Signals on Undirected Graphs

Rabeetha Velsamy, Radha Ramakrishnan

We study a shift invariant space on an undirected graphs $G$ having $N$ vertices. We obtain a characterization theorem for a system of generalized translates $\{T_{i}g : 1\leq i\le…

cs.IT2025

Optimal shift-invariant spaces from uniform measurements

Rohan Joy, Radha Ramakrishnan

Let $m$ be a positive integer and $C$ be a collection of closed subspaces in $L^{2} (R)$ . Given the measurements $\mathcal{F}_Y=\left\lbrace \left\lbrace y_k^1 \rig…

math.CA2024

Discrete Calderon condition for the twisted wavelet system

Radha Ramakrishnan, Rabeetha Velsamy

In this paper, we obtain an analogue of the discrete Calderon condition and prove that this condition is sufficient for an orthonormal twisted wavelet system to be complete in L^{2…

math.FA2023

Twisted shift preserving operators on $L^{2} (R^{2 n})$

Rabeetha Velsamy, Radha Ramakrishnan

We introduce the J map using the Zak transform associated with the Weyl transform on $L^{2} (R^{2 n})$ . We obtain a decomposition for a twisted shift-invariant subspace of $…

math.CA2023

Zak transform associated with the Weyl transform and the system of twisted translates on R^{2n}

Radha Ramakrishnan, Rabeetha Velsamy

We introduce the Zak transform on $L^{2} (R^{2 n})$ associated with the Weyl transform. By making use of this transform, we define a bracket map and prove that the system of…

math.FA2022

The system of translates and the special affine Fourier transform

Md Hasan Ali Biswas, Frank Filbir, Radha Ramakrishnan

The translation operator $T^{A}$ associated with the special affine Fourier transform (SAFT) $F_{A}$ is introduced from harmonic analysis point of view. The analogues of Wend…

math.FA2022

Systems of Left Translates and Oblique Duals on the Heisenberg Group

S. R. Das, P. Massopust, R. Radha

In this paper, we characterize the system of left translates ${L_{(2 k, l, m)} g : k, l, m \in Z}$ , $g \in L^{2} (H)$ , to be a frame sequence or a \emph{Riesz} sequence in te…

math.FA2021

B-splines on the Heisenberg group

Santi R. Das, Peter R. Massopust, Radha Ramakrishnan

In this paper, we introduce a class of $B$ -splines on the Heisenberg group $H$ and study their fundamental properties. Unlike the classical case, we prove that there does…