Fourier Integral Operators with Fold Singularities

An Fio Calculus for Marine Seismic Imaging, Ii: Sobolev Estimates

We establish sharp L2-Sobolev estimates for classes of pseudodifferential operators with singular symbols [27, 20] whose non-pseudodifferential (Fourier integral operator) parts exhibit two-sided fold singularities. The operators considered include both singular integral operators along curves in R2 with simple inflection points and normal operators arising in linearized seismic imaging in the ...

The Geodesic X-ray Transform with Fold Caustics

We give a detailed microlocal study of X-ray transforms over geodesics-like families of curves with conjugate points of fold type. We show that the normal operator is the sum of a pseudodifferential operator and a Fourier integral operator. We compute the principal symbol of both operators and the canonical relation associated to the Fourier integral operator. In two dimensions, for the geodesi...

Integral Operators with Singular Canonical Relations

We derive certain estimates and asymptotics for oscillatory integral operators with degenerate phase functions, concentrating our attention on the situation when one of the projections from the associated canonical relation is a Whitney fold. We discuss related topics: convexity, higher order degeneracy of canonical relations, and almost orthogonality. In the second part of the paper, we apply ...

Fourier Integral Operators with Cusp Singularities

Estimates for Generalized Radon Transforms

Sobolev and L p ? L q estimates for degenerate Fourier integral operators with fold and cusp singularities are discussed. The results for folds yield sharp estimates for restricted X-ray transforms and averages over non-degenerate curves in R 3 and those for cusps give sharp L 2 estimates for restricted X-ray transforms in R 4. In R 4 , sharp Lebesgue space estimates are proven for a class of m...