Ray marching method visualizes flat surfaces efficiently.
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Ray-marching method visualizes 8 Thurston geometries in real-time.
Paper proves March's criterion for transience on symmetric manifolds.
This short note serves as a historical introduction to the Hopf problem: "Does there exist a complex structure on ?" This unsolved mathematical question was the subject of the Conference "MAM 1 (Non-)Existence of Complex Structures on ", which took place at Philipps-Universität Marburg, Germany, between M…
Study extends geodesic ray transform results to orientable surfaces.
ObSuRF converts a single image into a 3D model with NeRFs.
Ray-Singer torsion is a mathematical concept with applications in physics.
In this paper we review the well-known fact that the only spheres admitting an almost complex structure are S^2 and S^6. The proof described here uses characteristic classes and the Bott periodicity theorem in topological K-theory. This paper originates from the talk "Almost Complex Structures on Spheres" given by the …
Lecture notes from the Third International School on Geometry and Physics at the Centre de Recerca Matematica in Barcelona, March 26--30, 2012.
We show that any grafting ray in Teichmüller space is (strongly) asymptotic to some Teichmüller geodesic ray. As an intermediate step we introduce surfaces that arise as limits of these degenerating Riemann surfaces. Given a grafting ray, the proof involves a Teichmüller ray with a conformally equivalent limit, and bui…
Survey on broken ray transforms and open problems.
We reduce the broken ray transform on some Riemannian manifolds (with corners) to the geodesic ray transform on another manifold, which is obtained from the original one by reflection. We give examples of this idea and present injectivity results for the broken ray transform using corresponding earlier results for the …
We study rays and co-rays in the Wasserstein space () whose ambient space is a complete, separable, non-compact, locally compact length space. We show that rays in the Wasserstein space can be represented as probability measures concentrated on the set of rays in the ambient spac…
Three disjoint rays in euclidean 3-space form Borromean rays provided their union is knotted, but the union of any two components is unknotted. We construct infinitely many Borromean rays, uncountably many of which are pairwise inequivalent. We obtain uncountably many Borromean hyperplanes.
Infinite clique of rays in plane minus Cantor set.
Study light ray transform in pseudo-Euclidean space, derive inversion formula, and prove stability.
Unique geodesics selected by energy minimization in Teichmüller space.
The article recovers tensor fields from partial data using weighted divergent ray transforms.
The ray graph is a Gromov hyperbolic graph on which the mapping class group of the plane minus a Cantor set acts by isometries. We give a description of the Gromov boundary of the ray graph in terms of cliques of long rays on the plane minus a Cantor set. As a consequence, we prove that the Gromov boundary of the ray g…
Regularity results for geodesic X-ray transform on nonsmooth manifolds
Local X-ray transform works well near boundaries in hyperbolic spaces.
Paper shows invertibility of tensor X-ray transform on certain manifolds.
New proofs of Donaldson-Uhlenbeck-Yau theorem using geodesic rays.
We consider the broken ray transform on Riemann surfaces in the presence of an obstacle, following earlier work of Mukhometov. If the surface has nonpositive curvature and the obstacle is strictly convex, we show that a function is determined by its integrals over broken geodesic rays that reflect on the boundary of th…
Study proves uniqueness for ray transform on surfaces with obstacles.
The study examines the asymptotic behavior of extremal length in Teichmüller space.
Local invertibility of ray transforms on convex manifolds.
This article contains a detailed study, in the toric case, of the test configuration geodesic rays defined by Phong-Sturm. We show that the `Bergman approximations' of Phong-Sturm converge in C^1 to the geodesic ray and that the geodesic ray itself is C^{1,1} and no better. The \kahler metrics associated to the geodesi…
The natural topological, differentiable and geometrical structures on the space of light rays of a given spacetime are discussed. The relation between the causality properties of the original spacetime and the natural structures on the space of light rays are stressed. Finally, a symplectic geometrical approach to the …
Study on Teichmüller rays' asymptotic behavior and distances.
In this paper, we consider the asymptotic behavior of two Teichmüller geodesic rays determined by Jenkins-Strebel differentials, and we obtain a generalization of a theorem in \cite{Amano14}. We also consider the infimum of the asymptotic distance in shifting base points of the rays along the geodesics. We show that th…
Study shows stability in X-ray transform on specific hyperbolic manifolds.
This PhD thesis studies the broken ray transform, a generalization of the geodesic X-ray transform where geodesics are replaced with broken rays that reflect on a part of the boundary. The fundamental question is whether this transform is injective. We employ four different methods to approach this question, and each o…
These are lecture notes mainly aimed at graduate students on selected aspects of generalized geometry: in particular generalized complex and Kaehler structures and generalized holomorphic bundles. They are based on lectures given in March 2010 at the Chinese University of Hong Kong.
Injectivity result for light ray transform on Lorentzian manifolds.
New methods model gamma-ray data to better understand Galactic emissions.
New Teichmüller geodesic rays found with unique foliations.
We construct symplectic and Kähler ray reduced spaces and discuss their relation with the Marsden-Weinstein (point) reduction. This Kähler reduction is well defined even when the momentum value is not totally isotropic. The compatibility of the ray reduction with the cone construction and the Boothby-Wang fibration is …
These are lecture notes on scale calculus and M-polyfolds written for a graduate course at UNICAMP March-June 2018 and an advanced mini-course given during the biannual meeting of Brazilian mathematicians, CBM-32, at IMPA in August 2019.
Ray tracing sampler improves neural network sampling efficiency and resilience.
The study evaluates different probability models for uncertainty visualization using entropy calculations.
Optical interpretation of Euler's angle problem for caustics of light rays.
Symplectic manifold rays can be removed without changing the manifold's structure.
Characterizes closures of test configurations and algebraic singularity types.
Injective X-ray transform on Heisenberg group for regular functions.
Paper proves injectivity of non-abelian X-ray transform on certain spaces.
We show that the diameter of the skinning map of an acylindrical hyperbolic 3-manifold M is bounded on thick Teichmueller geodesic rays by a constant depending only on the thickness of the ray and the topological type of the boundary of M.
New metric spaces for geodesic rays in cohomology classes.