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Susovan Pramanik

Publications and source records attributed to Susovan Pramanik.

5 recordsLinked to original sources

Eigenfunction equivalence for the fractional Laplace-Beltrami operator and the classical Helmholtz equation

In this article we study the spectral problem related to the fractional Laplace-Beltrami equation on $(\mathbb{R}^d,g)$ and establish its equivalence with the classical anisotropic Helmholtz equation. The proof is based on Seeley's construction of complex powers of elliptic operators and the pseudodifferential symbolic calculus. As an application, we describe the related fixed-frequency inverse scattering problem of recovering the metric from the scattering amplitude.

math.AP

On a nonlocal non-linear inverse scattering problem

In this article, we study the inverse scattering problem for the nonlinear fractional Helmholtz equation with cubic nonlinearity in three dimensions, where we recover a compactly supported potential from scattering amplitude.

math.AP

Anisotropic Calder\'{o}n problem for a logarithmic Schr\"{o}dinger operator of order $2+$ on closed Riemannian manifolds

In this article, we study the anisotropic Calder\'on problems for the non local logarithimic Schr\"odinger operators $(-\Delta_g+m)\log{(-\Delta_g+m)}+V$ with $m>1$ on a closed, connected, smooth Riemannian manifold of dimension $n\geq2$. We will show that, for the operator $(-\Delta_g+m)\log{(-\Delta_g+m)}+V$, the recovery of both the Riemannian metric and the potential is possible from the Cauchy data, in the setting of a common underlying manifold with varying metrics. This result is unconditional. The last result can be extended to the case of setwise distinct manifolds also. In particular, we demonstrate that for setwise distinct manifolds, the Cauchy data associated with the operator $(-\Delta_g+m)\log{(-\Delta_g+m)}+V$, measured on a suitable non-empty open subset, uniquely determines the Riemannian manifold up to isometry and the potential up to an appropriate gauge transformation. This particular result is unconditional when the potential is supported entirely within the observation set. In the more general setting-where the potential may take nonzero values outside the observation set-specific geometric assumptions are required on both the observation set and the unknown region of the manifold.

math.AP