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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

169,181 papers · 148 categories

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4692137183 · Jun 202019922001200920182026
48 results for x-ray transform

Paper shows invertibility of tensor X-ray transform on certain manifolds.

problem Invertibility of tensor X-ray transform on asymptotically conic manifolds.
method Used 1-cusp pseudodifferential operator algebra and modified solenoidal gauge condition.
result Invertibility of tensor X-ray transform up to natural obstruction.

Sharp mapping properties and regularization for X-ray transform on disks of constant curvature.

problem Sharp mapping properties and regularization of X-ray transform.
method Derive functional relations and mapping properties using elliptic differential operators.
result Theoretical possibility of regularized inversions for X-ray transform.

Local X-ray transform works well near boundaries in hyperbolic spaces.

problem Injectivity of X-ray transform near boundaries for hyperbolic metrics.
method Local injectivity proof for geodesic X-ray transform on asymptotically hyperbolic manifolds.
result Local injectivity near a boundary point for X-ray transform in dimensions 3 and higher, up to O(ρ5)O(ρ^5).

Study characterizes X-ray transform kernel for periodic slabs and related manifolds.

problem Characterizing the kernel of X-ray transform for tensor fields on periodic slabs.
method Characterization of the kernel for L2L^2-regular mm-tensors on [0,1]imesTn[0,1] imes\mathbb T^n.
result Kernel characterization extends to more general manifolds, including the Möbius strip.

Functions with constant geodesic X-ray transform are restricted to manifolds with specific geometrical properties.

problem Existence of functions with constant geodesic X-ray transform on manifolds.
method Analyzing the geometrical properties of manifolds based on the existence of such functions.
result Functions with constant geodesic X-ray transform impose specific geometrical restrictions on the manifold.

Injectivity of X-ray transform on solenoidal tensors proven for certain manifolds.

problem Injectivity of X-ray transform on solenoidal tensors on manifolds with hyperbolic trapped set.
method Proof of equivalence principle concerning injectivity and surjectivity of operators on symmetric solenoidal tensors.
result Injectivity of X-ray transform on solenoidal tensors of any order for surfaces with hyperbolic trapped set.

Paper proves injectivity of non-abelian X-ray transform on certain spaces.

problem Injectivity of non-abelian X-ray transform on asymptotically hyperbolic spaces.
method Gauge equivalence for unitary connections and skew-Hermitian Higgs fields.
result Injectivity result for non-abelian X-ray transform over skew-Hermitian Higgs fields.

New proof of injectivity for broken non-abelian X-ray transform in Minkowski space.

problem Injectivity of broken non-abelian X-ray transform in Minkowski space.
method Stability estimate considering gauge, light-sink connections, Bayesian inversion.
result Consistent recovery of light-sink connections from noisy data.

Study proper sampling for X-ray transforms on simple surfaces.

problem Proper discretizing and sampling issues related to geodesic X-ray transforms on simple surfaces.
method Provide minimal sampling rates for faithful reconstruction, quantify sampling quality, and predict artifacts.
result Minimal sampling rates and artifact prediction for geodesic X-ray transforms on simple surfaces.

Study X-ray transform on manifolds, desingularize, and improve mapping properties.

problem Characterize mapping properties of X-ray transform and its adjoint on manifolds with strictly convex boundary.
method Use b-fibrations, desingularize, and apply Melrose's Pushforward Theorem to analyze polyhomogeneous functions.
result Improved mapping properties of X-ray transform and its adjoint, recovering sharp results.

Support theorem proved for X-ray transform on certain non-compact manifolds.

problem Support theorem for X-ray transform on non-compact manifolds with conjugate points.
method Use of plane covers and support theorem for simple manifolds by Krishnan.
result Support theorem proved for simply connected 2-step nilpotent Lie groups and some non-homogeneous 3D manifolds.

New insights into X-ray transform on hyperbolic disk, with functional relations and range characterizations.

problem Understanding the X-ray transform on hyperbolic geometry.
method Derived new singular value decompositions, range characterizations, and intertwining relations with wedge-type differential operators.
result Sharp understanding of boundary behavior and invertibility settings for the X-ray transform.

The geodesic X-ray transform on disks of constant curvature is characterized and decomposed.

problem Characterizing and decomposing the geodesic X-ray transform on disks of constant curvature.
method Explicit construction of a basis for the range and co-kernel, derivation of Singular Value Decomposition.
result Explicit Singular Value Decomposition for the geodesic X-ray transform.

Study shows certain manifolds uniquely determined by X-ray data.

problem Determining manifolds from X-ray data.
method Injectivity of X-ray transform over symmetric solenoidal 2-tensors.
result Smooth compact manifolds with strictly convex boundary, no conjugate points, and hyperbolic trapped set are locally marked boundary rigid.

Injectivity of geodesic X-ray transform on low-regularity manifolds.

problem Injectivity of geodesic X-ray transform on manifolds with low regularity.
method Calculus of differential and curvature operators on non-smooth structures.
result Injectivity of geodesic X-ray transform on simple Riemannian manifolds with C1,1C^{1,1}-regularity.

In this paper we consider the geodesic X-ray transform with attenuation coefficient as a combination of smooth complex function and 1-form. We show that attenuated X-ray transform applied to the pair of tensors is injective modulo the natural obstruction.

2012-04-19abs ↗pdf ↗

Unique continuation for X-ray transforms of one-forms with partial data.

problem Proving unique continuation for X-ray transforms of one-forms with limited data.
method Proved unique continuation for the normal operator of X-ray transforms of one-forms, leading to partial data results.
result Unique continuation for X-ray transforms of one-forms with partial data.

We study the geodesic X-ray transform XX on compact Riemannian surfaces with conjugate points. Regardless of the type of the conjugate points, we show that we cannot recover the singularities and therefore, this transform is always unstable (ill-posed). We describe the microlocal kernel of XX and relate it to the con…

2014-02-22abs ↗pdf ↗

Study geodesic X-ray transform and streaking artifacts on simple surfaces or spaces of constant curvature.

problem Streaking artifacts in CT images due to metal regions.
method Geodesic X-ray transform on nontrapping compact Riemannian manifolds with strictly convex boundaries.
result Streaking artifacts result from conormal singularities along common tangent geodesics.

We show injectivity of the X-ray transform and the dd-plane Radon transform for distributions on the nn-torus, lowering the regularity assumption in the recent work by Abouelaz and Rouvière. We also show solenoidal injectivity of the X-ray transform on the nn-torus for tensor fields of any order, allowing the tensor…

2014-02-25abs ↗pdf ↗

In this paper we consider the local X-ray transform for general flows. We extend the results on the local and global invertibility of the geodesic ray transform proved by Uhlmann and Vasy \cite{UV} to the X-ray transform for a general flow. The key improvement is that our argument for the ellipticity of the conjugated …

2013-04-25abs ↗pdf ↗

For Anosov flows preserving a smooth measure on a closed manifold M\mathcal{M}, we define a natural self-adjoint operator ΠΠ which maps into the space of invariant distributions in u<0Hu(M)\cap_{u<0} H^{u}(\mathcal{M}) and whose kernel is made of coboundaries in s>0Hs(M)\cup_{s>0} H^{s}(\mathcal{M}). We describe relations to Liv…

2014-08-20abs ↗pdf ↗

Study geodesic X-ray transforms on hyperbolic surfaces, proposing new reconstruction methods.

problem Inverting geodesic X-ray transforms for symmetric tensor fields on asymptotically hyperbolic surfaces.
method Developed a decomposition theorem for m-tensor fields, used Guillemin-Kazhdan operators and 0-calculus, and provided explicit reconstruction methods.
result Explicit reconstruction methods for even tensor fields from their X-ray transform or normal operator.

Under a convexity assumption on the boundary we solve a local inverse problem, namely we show that the geodesic X-ray transform can be inverted locally in a stable manner; one even has a reconstruction formula. We also show that under an assumption on the existence of a global foliation by strictly convex hypersurfaces…

2012-10-07abs ↗pdf ↗

Sharp stability estimate for geodesic ray transform on simple manifolds.

problem Stability estimate for geodesic ray transform of tensor fields.
method Microlocal analysis and structured range of geodesic ray transform.
result Sharp L2oH1/2L^2 o H^{1/2} stability estimate for tensor fields of order 0, 1, and 2.

Study benchmarks uncertainty quantification in chest X-ray classification.

problem Reliable uncertainty quantification for medical AI models.
method Evaluation of 13 uncertainty quantification methods on MIMIC-CXR-JPG dataset.
result Insights into effectiveness and disentanglement of epistemic and aleatoric uncertainties.