N. Tomar

activity

20242026

collaborators

6 papers

math.FA2026

Rigidity of the structured singular value and applications

Sourav Pal, Nitin Tomar

The structured singular value $μ_{E}$ for a linear subspace $E$ of $M_{n} (C)$ is defined by \[ μ_E(A)=1 / \inf\{\|X\| \ : \ X \in E, \ \det(I_n-AX)=0 \} \quad (A \in M_n(\mathb…

math.CV2026

A domain in $C^{4}$ and its connection with $μ$ -synthesis problem

Sourav Pal, Nitin Tomar

We explore a domain $F$ in $C^{4}$ that has structural similarities with the hexablock $H \subset C^{4}$ . It leads to the question if these two domains…

math.FA2025

Constrained dilation and $Γ$ -contractions

Sourav Pal, Nitin Tomar

A commuting pair of Hilbert space operators having the closed symmetrized bidisc \[ Γ=\{(z_1+z_2, z_1z_2) \in \mathbb C^2 \ : \ |z_1| \leq 1, |z_2| \leq 1\} \] as a spectral set is…

math.FA2025

Dilation on an annulus and von Neumann's inequality on certain varieties in the biball

Sourav Pal, Nitin Tomar

We give an alternative proof to Agler's famous result on success of rational dilation on an annulus by an application of a result due to Dritschel and McCullough. We show interplay…

math.FA2025

On doubly commuting operators in $C_{1, r}$ class and quantum annulus

Nitin Tomar

For $0 < r < 1$ , let $A_{r} = {z \in C : r < ∣ z ∣ < 1}$ be the annulus with boundary $\partial A_{r} = T \cup r T$ , wher…

math.FA2024

Classification and dilation for $q$ -commuting $2 \times 2$ scalar matrices

Sourav Pal, Prajakta Sahasrabuddhe, Nitin Tomar

A tuple $T = (T_{1}, \dots, T_{k})$ of operators on a Hilbert space $H$ is said to be \textit{ $q$ -commuting with} $∥ q ∥ = 1$ or simply $q$ -\textit{commuting} if ther…

Rigidity of the structured singular value and applications

A domain in C4 and its connection with μ-synthesis problem

Constrained dilation and Γ-contractions

Dilation on an annulus and von Neumann's inequality on certain varieties in the biball

On doubly commuting operators in C1,r​ class and quantum annulus

Classification and dilation for q-commuting 2×2 scalar matrices

A domain in $C^{4}$ and its connection with $μ$ -synthesis problem

Constrained dilation and $Γ$ -contractions

On doubly commuting operators in $C_{1, r}$ class and quantum annulus

Classification and dilation for $q$ -commuting $2 \times 2$ scalar matrices