Transforms surfaces into spheres using mean curvature.
problem Transforming surfaces into spheres.
method Transformation based on mean curvature.
result Surfaces morphed into round spheres.
The notion of a generalized harmonic inverse mean curvature surface in the Euclidean four-space is introduced. A backward Bäcklund transform of a generalized harmonic inverse mean curvature surface is defined. A Darboux transform of a generalized harmonic inverse mean curvature surface is constructed by a backward Bäck…
The conformal geometry of spacelike surfaces in 4-dimensional Lorentzian space forms has been studied by the authors in a previous paper, where the so-called polar transform was introduced. Here it is shown that this transform preserves spacelike conformal isothermic surfaces. We relate this new transform with the know…
Study extends geodesic ray transform results to orientable surfaces.
problem Characterize and stabilize mixed and transverse ray transforms on surfaces.
method Algebraic arguments applied to various geometries and ray transforms.
result Characterization of kernel and stability for mixed and transverse ray transforms on orientable surfaces.
The paper discusses a new method for constructing two-step Darboux transforms of isothermic surfaces.
problem Constructing two-step Darboux transforms of isothermic surfaces.
method Sym-type construction using parallel sections of the associated family.
result All two-step Darboux transforms of an isothermic surface are given without further integration.
The basic theory on the conformal geometry of timelike surfaces in pseudo-Riemannian space forms is introduced, which is parallel to the classical framework of Burstall etc. for spacelike surfaces. Then we provide a discussion on the transforms of timelike (±)−isothermic surfaces (or real isothermic, complex isothe…
Transforming quadrangulations on surfaces with moves.
problem Transforming quadrangulations of the same surface.
method Two-dimensional local cubical Pachner moves and non-local subdivision transformations.
result Any two quadrangulations of the same surface can be transformed into one another.
Minimal surfaces proof via Darboux transformations.
problem Minimal surface properties and transformations.
method Christoffel, Goursat, and Darboux transformations of isothermic surfaces.
result Simple proof of Darboux pairs relation.
In this paper, we generalize the polar transforms of spacelike isothermic surfaces in Q14 to n-dimensional pseudo-Riemannian space forms Qrn. We show that there exist c−polar spacelike isothermic surfaces derived from a spacelike isothermic surface in Qrn, which are into Srn+1(c), Hr−1n+1(c)…
New CMC surfaces with dihedral symmetry constructed from Darboux transforms.
problem Constructing closed CMC surfaces with specific symmetries.
method Using Darboux transforms on multiple covers to create new CMC surfaces.
result Explicit parametrisations of new closed CMC surfaces with dihedral symmetry.
Permutability of surface transforms yields discrete analogs.
problem Discretization of smooth surfaces with specific properties.
method Permutability of transforms of smooth surfaces.
result Discrete surfaces with discrete analogs of original properties.
We study an analogue of the classical Bianchi-Darboux transformation for L-isothermic surfaces in Laguerre geometry, the Bianchi-Darboux transformation. We show how to construct the Bianchi-Darboux transforms of an L-isothermic surface by solving an integrable linear differential system. We then establish a permutabili…
New Bäcklund transformations for discrete pseudospherical surfaces of revolution are found.
problem Constructing new non-rotational discrete pseudospherical surfaces.
method Explicit parametrizations and Bäcklund transformations for discrete constant negative Gaussian curvature surfaces of revolution.
result Conditions for Bäcklund transformations to preserve periodicity are provided.
Study on gauge transformations on Riemannian surfaces with boundary using heat flow method.
problem Analyzing gauge transformations on Riemannian surfaces with boundary.
method Heat flow method for local and long-time existence of solutions.
result Local and long-time existence of generalized solutions proved.
Study characterizes kernel of mixed ray transform on simple surfaces.
problem Characterizing the kernel of mixed ray transform on simple surfaces.
method Characterization of the kernel through analysis of mixed ray transform on simple 2D Riemannian manifolds.
result Characterization of the kernel of the mixed ray transform on simple surfaces.
Transforms study meromorphically isothermic surfaces near singular points.
problem Analyzing meromorphically isothermic surfaces near singular points.
method Apply Darboux and Calapso transformations to patches of surfaces.
result Transformed patches exhibit continuity around singular points.
Geometric approach uses Bäcklund transformations to create integrable discrete analogs of surface nets.
problem Creating integrable discrete analogs of surface nets and conjugate nets.
method Interpreting classical differential geometry results through Bäcklund transformations and applying permutability properties.
result Integrable discrete analogs of asymptotic and conjugate nets are constructed.
The study characterizes channel surfaces in Lie sphere geometry and their transformations.
problem Characterizing channel surfaces in Lie sphere geometry.
method Using Ω0-surfaces and Dupin cyclide congruences to study transformations and Ribaucour pairs. result Characterization of channel surfaces and their transformations.
This work is dedicated to the study of the Moebius invariant class of constrained Willmore surfaces and its symmetries. We define a spectral deformation by the action of a loop of flat metric connections; Baecklund transformations, by applying a dressing action; and, in 4-space, Darboux transformations, based on the so…
We exhibit several transformations of surfaces in R^4. First, one that takes a flat surface and gets a surface with flat normal bundle; then, one that takes a surface with flat normal bundle and gets a flat surface; finally, a one-parameter family of transformations on a flat surface with flat normal bundle and gives a…
We use the dressing method to construct transformations of constrained Willmore surfaces in arbitrary codimension. An adaptation of the Terng--Uhlenbeck theory of dressing by simple factors to this context leads us to define Bäcklund transforms of these surfaces for which we prove Bianchi permutability. Specialising to…
We define a transformation on harmonic maps from a Riemann surface into the 2-sphere which depends on a complex parameter, the so-called mu-Darboux transformation. In the case when the harmonic map N is the Gauss map of a constant mean curvature surface f and the parameter is real, the mu-Darboux transformation of -N i…
In trying to generalize Bianchi's Bäcklund transformation of quadrics to Bäcklund transformations of isometric deformations of other (classes of) surfaces, we investigate basic features of the isometric deformation of surfaces via the Bäcklund transformation with isometric correspondence of leaves of a general nature (…
Two new methods for injective ray transforms of tensor fields on surfaces are introduced.
problem Injective ray transforms for tensor fields on surfaces.
method Two approaches: weights varying along geodesic flow and transverse ray transforms.
result Constructive solutions for tensor tomography on simple surfaces.
A Darboux transformation for polarized space curves is introduced and its properties are studied, in particular, Bianchi permutability. Semi-discrete isothermic surfaces are described as sequences of Darboux transforms of polarized curves in the conformal n-sphere and their transformation theory is studied. Semi-discre…
We define two transforms between minimal surfaces with non-circular ellipse of curvature in the 5-sphere, and show how this enables us to construct, from one such surface, a sequence of such surfaces. We also use the transforms to show how to associate to such a surface a corresponding ruled minimal Lagrangian submanif…
The paper explores Guichard nets and their dual properties.
problem Understanding Guichard nets and their dual systems.
method Introduced Combescure transformations and Bäcklund-type transformations.
result Permutability theorem for dual systems of Guichard nets.
The study characterizes polynomial conserved quantities for Lie applicable surfaces.
problem Characterizing polynomial conserved quantities for Lie applicable surfaces.
method Gauge theoretic approach for Lie applicable surfaces, including isothermic, Guichard, and L-isothermic surfaces. result Induced transformations of Lie applicable surfaces for well-known transformations and new Bäcklund-type transformation for linear Weingarten surfaces.
In this note we study logarithmic transformations in the sense of differential topology on two fibers of the Hopf surface. It is known that such transformations are susceptible to yield exotic smooth structures on four-manifolds. We will show here that this is not the case for the Hopf surface, all integer homology Hop…
The paper constructs isothermic surfaces using Ribaucour transformations.
problem Creating isothermic surfaces with specific properties.
method Applying Ribaucour transformations to the cylinder and obtaining families of complete isothermic surfaces.
result Obtained families of isothermic surfaces with unique properties (e.g., n-bubble surfaces, planar ends, no constant mean curvature).
Study proves uniqueness for ray transform on surfaces with obstacles.
problem Uniqueness of functions and 1-forms on surfaces with reflecting obstacles.
method Broken ray transform on twisted geodesics with nonpositive curvature and reflecting boundary.
result Proves uniqueness result for sums of functions and 1-forms.
Paper classifies minimal graph transformations into new families of surfaces.
problem Classifying minimal graph transformations into new families of surfaces.
method Formulated and solved a coupled system of partial differential equations, reduced to solving an ordinary differential equation.
result Established rigorous equivalence to a modified problem for a harmonic function, yielding new families of minimal surfaces.
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.
Automorphisms of Kodaira surfaces are shown to be affine transformations.
problem Characterizing automorphisms of Kodaira surfaces.
method Analyzing lifts to the universal cover and conditions on affine transformations.
result Precise description of Kodaira surfaces' automorphism groups.
Transforms Dirac operators to relate surfaces in 4D.
problem Relating surfaces in 4D via Dirac operators.
method Constructs Moutard transformation for 2D Dirac operators.
result Explicit example creates double points on spectral curve.
Gauge theory explains Lie applicable surfaces.
problem Understanding Lie applicable surfaces.
method Gauge-theoretic approach.
result Coincides with classical notions of Ω- and Ω0-surfaces. New definition of Bäcklund transformation for surface isometric deformation.
problem Defining Bäcklund transformation in surface isometric deformation.
method Proving generic 4D integrable rolling distribution splits into 1D family of 3D distributions.
result Introducing new definition of Bäcklund transformation.
Transforms solutions of Davey-Stewartson II equation geometrically.
problem Solving the Davey-Stewartson II equation.
method Moutard transform and spinor representation of surfaces.
result Constructs examples of solutions with smooth initial data losing regularity.
Invariants for surfaces up to rigid transformations, with a comeagre subset retrieval algorithm.
problem Identifying compact surfaces up to rigid transformations.
method Degree four polynomials in moments of delta function, effective inversion algorithm.
result Invariants and retrieval algorithm work on a comeagre subset of surfaces.
After the surface theory of Möbius geometry, this study concerns a pair of conformally immersed surfaces in n-sphere. Two new invariants θ and ρ associated with them are introduced as well as the notion of touch and co-touch. This approach is helpful in research about transforms of certain surface classes. As an …
Study characterizes geodesic ray transform on surfaces, isolating and separating sub-ranges.
problem Characterizing the range of the attenuated geodesic ray transform on surfaces.
method Isolating and separating sub-ranges of sums of functions and one-forms, deriving new inversion formulas.
result Range characterizations and new inversion formulas for geodesic ray transform.
Unified description of Weierstrass-type representations.
problem Creating surfaces with special curvature properties.
method Unified description using classical transformation theory of Ω-surfaces.
result Unified understanding of Weierstrass-type representations.
In this study, we define a family of ruled surfaces in the Euclidean 3-space E^3 and called similar ruled surfaces. We obtain some properties of these special surfaces and we show that developable ruled surfaces form a family of similar ruled surfaces if and only if the striction curves of the surfaces are similar curv…
Transforms curves and surfaces for efficient geometric analysis.
problem Efficiently analyzing and comparing curves and surfaces.
method Square root velocity transformation for curves and intrinsic comparison for surfaces.
result Fundamental geometric properties of curves under the transformation.
This research examines anisotropic conformal transformations of pseudo-Finsler surfaces.
problem Investigating anisotropic conformal transformations of conic pseudo-Finsler surfaces.
method Using modified Berwald frame, the study finds necessary and sufficient conditions for anisotropic conformal transformations and analyzes geometric properties.
result Necessary and sufficient conditions for anisotropic conformal transformations of pseudo-Finsler surfaces are derived.
Reconstructs geodesic ray transforms on simple Riemannian surfaces with connections.
problem Reconstructing geodesic ray transforms on Riemannian surfaces with connections.
method Derives reconstruction formulas and injectivity conditions for geodesic ray transforms with connections.
result Injectivity of geodesic ray transforms in a neighborhood of constant curvature metrics and non-unitary connections.
Study of line congruences for Appell's rank-4 hypergeometric functions.
problem Understanding line congruences for Appell's rank-4 hypergeometric functions.
method Derived original formulae for Laplace transform of rank-4 system, applied to geometry of surfaces defined by these functions.
result Natural line congruences for Laplace transforms of Appell's rank-4 functions form a W-congruence.
Given two compact hyperkähler surfaces X and Y and a holomorphic vector bundle Q on X×Y, which is a generalized instanton, one can define a Fourier-Mukai transform, which, under suitable assumptions, maps vector bundles on X to vector bundles on Y. If X and Y are dual complex tori, this transform …