8 citations · 9 across the 5 of their papers we have counts for
5 papers
Spectral Geometry of Cosmological and Event Horizons for Kerr-Newman de Sitter metrics
Martin Engman, Gerardo A. Santana
We study the Laplace spectra of the intrinsic instantaneous metrics on the event and cosmological horizons of a Kerr-Newman de Sitter space-time and prove that the spectral data fr…
Intrinsic Spectral Geometry of the Kerr-Newman Event Horizon
Martin Engman, Ricardo Cordero Soto
We uniquely and explicitly reconstruct the instantaneous intrinsic metric of the Kerr-Newman Event Horizon from the spectrum of its Laplacian. In the process we find that the angul…
A Note on Isometric Embeddings of Surfaces of Revolution
Martin Engman
In the special case of S^1 invariant metrics on S^2, we find necessary and sufficient conditions for the existence of isometric embeddings into the canonical R^3, in other words: a…
The spectrum and isometric embeddings of surfaces of revolution
Martin Engman
An upper bound on the first S^1 invariant eigenvalue of the Laplacian for invariant metrics on the 2-sphere is used to find obstructions to the existence of isometric embeddings of…
Sharp Bounds for Eigenvalues and Multiplicities on Surfaces of Revolution
Martin Engman
We find sharp upper bounds for the multiplicities and the numerical values of all the distinct eigenvalues on a surface of revolution diffeomorphic to the sphere.