Given a real-valued function c defined on the cartesian product of a generic Carnot group $\G$ and the first layer V1 of its Lie algebra, we introduce a notion of c horizontal convex (c H-convex) function on $\G$ as the supremum of a suitable family of affine functions; this family is defined pointwisely, and …
Formula calculates equilibria of convex bodies based on evolute winding number.
problem Determining equilibria of convex bodies in terms of their geometric properties.
method Formula derived from winding number of evolute of convex body boundary.
result Formula extends to cases where center of mass lies on evolute.
We find a different approach to define convex functions in the sub-Riemannian setting. A function on a sub-Riemannian manifold is nonholonomically geodesic convex if its restriction to any nonholonomic (straightest) geodesic is convex. In the case of Carnot groups, this definition coincides with that by Danniell-Garofa…
We investigate the minimal and isoperimetric surface problems in a large class of sub-Riemannian manifolds, the so-called Vertically Rigid spaces. We construct an adapted connection for such spaces and, using the variational tools of Bryant, Griffiths and Grossman, derive succinct forms of the Euler-Lagrange equations …
Paper studies how certain hypersurfaces collapse in Hilbert space.
problem Collapse of hypersurfaces in Hilbert space.
method Investigates mean curvature flow with specific conditions.
result Invariant hypersurfaces collapse to group orbits under flow.
Characterizes Kähler-Berwald metrics on complex manifolds.
problem Identifying Kähler-Berwald metrics among strongly convex complex Finsler metrics.
method Geometric characterization using Cartan and Chern-Finsler connections.
result Characterizes Kähler-Berwald metrics in terms of parallelism of the canonical complex structure.
We characterize convex isoperimetric sets in the Heisenberg group endowed with horizontal perimeter. We first prove Sobolev regularity for a certain class of vector fields in the plane with bounded variation, related to the curvature equations. Then, by an approximation-reparameterization argument, we show that the bou…
Study rigid motions in 3D-Heisenberg group to define and relate geometric probabilities.
problem Define geometric quantities and probabilities in the 3D-Heisenberg group.
method Define density and measure for horizontal lines, use integral geometry.
result Show relationship between geometric probability and natural geometric quantity.
We investigate the notion of H-subdifferential and H-normal map of a function on the Heisenberg group, based on its sub-Riemannian structure. In particular, a characterization of the convexity of a function is given via the nonemptiness of the H-subdifferential at every point.
Study on shapes in Heisenberg group with convex body norms.
problem Characterize shapes in the Heisenberg group H1 induced by convex bodies. method Compute perimeter variation, define mean curvature, and analyze foliations.
result Existence of constant mean curvature spheres in the Heisenberg group.
Given a warped product space R×fN with logarithmically convex warping function f, we prove a relative isoperimetric inequality for regions bounded between a subset of a vertical fiber and its image under an almost everywhere differentiable mapping in the horizontal direction. In particular, given…
Study geodesics in Heisenberg groups with sub-Finsler metrics.
problem Characterize infinite geodesics in Heisenberg groups.
method Optimal control theory applied to sub-Finsler metrics.
result Proves infinite geodesics are horizontal lines under specific conditions.
Step 2 Carnot groups can approximate horizontal curves without error.
problem Approximating horizontal curves in step 2 Carnot groups.
method Verification of Lusin approximation for free Carnot groups of step 2 and preservation by homomorphisms.
result All step 2 Carnot groups admit Lusin approximation for horizontal curves.
Defines conformal submersion with horizontal distribution and provides necessary conditions for its existence.
problem Existence and conditions for conformal submersion with horizontal distribution.
method Definition and analysis of conformal submersion with horizontal distribution, dual connections, and necessary conditions.
result Necessary and sufficient conditions for conformal submersion with horizontal distribution and geodesics.
The horizontal Laplacian of a Riemannian submersion with totally geodesic fibers and an integrable horizontal distribution.
problem Studying spectral properties of the horizontal Laplacian
method Interpreting the horizontal Laplacian as a twisted Laplacian acting on a flat vector bundle
result The horizontal Laplacian is unitarily equivalent to a twisted Laplacian acting on the space of sections of a certain infinite-rank flat vector bundle over the base manifold
We describe explicit horizontal open books on some Seifert fibered 3--manifolds. We show that the contact structures compatible with these horizontal open books are Stein fillable and horizontal as well. Moreover we draw surgery diagrams for some of these contact structures.
We study some sub-Riemannian objects (such as horizontal connectivity, horizontal connection, horizontal tangent plane, horizontal mean curvature) in hypersurfaces of sub-Riemannian manifolds. We prove that if a connected hypersurface in a contact manifold of dimension more than three is noncharacteristic or with isola…
Study H-type foliations in sub-Riemannian geometry.
problem Understand and classify H-type foliations in sub-Riemannian geometry.
method Introduce and study H-type foliations, prove curvature bounds, and classify foliations with parallel structures.
result Prove curvature bounds and classify H-type foliations with parallel structures.
The study finds conditions for horizontal envelopes in a 3D-Heisenberg group.
problem Existence and conditions for horizontal envelopes in the 3D-Heisenberg group.
method Using support function on the xy-plane, derive necessary and sufficient conditions, and provide a method to construct horizontal envelopes.
result Necessary and sufficient conditions for the existence of horizontal envelopes in the 3D-Heisenberg group.
The paper studies critical points of horizontal energy functional in Riemannian foliations.
problem Analyzing critical points of horizontal energy functional in Riemannian foliations.
method Utilizing stress-energy tensor, establishing monotonicity formulas, and Jin-type theorems.
result Established monotonicity formulas for horizontally harmonic maps and transversally harmonic maps.
Study horizontal discs in fat distributions, proving their existence.
problem Existence of embedded horizontal discs in fat distributions.
method Analyzing nonlinear PDEs and proving local invertibility.
result Existence of germs of embedded horizontal discs.
The study develops inequalities for Riemannian foliations without bundle-like assumptions.
problem Developing inequalities for Riemannian foliations without restrictive conditions.
method Bochner theory and Bakry-Emery calculus for horizontal Laplacians, derived explicit Bochner formulas, generalized curvature dimension inequalities.
result Established generalized curvature dimension inequalities for Riemannian foliations.
Fundamental weight systems identified as quantum states.
problem Identifying which weight systems are quantum states.
method Analyzing the Cayley distance kernel on the symmetric group and its positivity.
result All fundamental gl(n)-weight systems are quantum states.
Affine and conformal submersions with horizontal distribution are studied in statistical manifolds.
problem Characterizing submersions and geodesics in statistical manifolds.
method Introducing conformal submersions with horizontal distribution and proving conditions for statistical manifold properties.
result Necessary and sufficient conditions for submersions and geodesics in statistical manifolds.
Study shows horizontal diameter of unit spheres is π for specific foliations.
problem Understanding horizontal diameter in unit spheres with specific foliations.
method Analyzing singular Riemannian foliations on unit spheres.
result Horizontal diameter of unit spheres is π for polar and infinitesimally polar actions.
The complexity of horizontality in twistor spaces on tori is infinite.
problem Complexity of horizontality in twistor spaces on tori.
method Analyzing the complexity of horizontality in the twistor space associated with an oriented vector bundle over a torus.
result The complexity of horizontality in the twistor space is expressed by a dense subset of S2 when it is infinite. We study unit horizontal bundles associated with Riemannian submersions. First we investigate metric properties of an arbitrary unit horizontal bundle equipped with a Riemannian metric of the Cheeger-Gromoll type. Next we examine it from the Gromov-Hausdorff convergence theory point of view, and we state a collapse the…
We describe explicit open books on arbitrary plumbings of oriented circle bundles over closed oriented surfaces. We show that, for a non-positive plumbing, the open book we construct is horizontal and the corresponding compatible contact structure is also horizontal and Stein fillable. In particular, we describe horizo…
Smooth 4-manifolds have simple horizontal decompositions.
problem Classifying smooth, closed, orientable 4-manifolds.
method Horizontal handlebody decomposition.
result Simplest horizontal decompositions classify closed 4-manifolds.
We deform a map into a Riemannian manifold that is horizontal with respect to a submersion onto a non-positively curved manifold and satisfies a Chow condition into a harmonic one through a horizontal homotopy.
New model for STSs with restricted horizontal gluings, focusing on maximal horizontal cylinders.
problem Modeling STSs with specific horizontal restrictions.
method Modified model with conjugacy classes of permutations to restrict horizontal gluings.
result Asymptotic analysis of components, genus distribution, and saddle connections.
Study on curvatures of surfaces in specific Lie groups.
problem Analyzing curvatures of surfaces in 3D contact sub-Riemannian Lie groups.
method Riemannian approximation scheme to derive formulas for curvatures.
result Classification of surfaces with constant horizontal curvatures.
In this paper, we study the regularized mean curvature flow starting from invariant hypersurfaces in a Hilbert space equipped with an isometric almost free Hilbert Lie group action whose orbits are minimal regularizable submanifolds, where "almost free" means that the stabilizers of the group action are finite. First w…
Examples of area-minimizing graphs with low regularity in a specific group.
problem Finding area-minimizing graphs with low regularity in a sub-Finsler Heisenberg group.
method Providing examples of entire area-minimizing horizontal graphs with prescribed singular sets.
result Examples of area-minimizing graphs that are locally Lipschitz but not necessarily smoother.
Study examines how hyperbolic metrics change over time.
problem Fine convergence properties of hyperbolic metrics.
method Analyzes horizontal families of hyperbolic metrics.
result Characterizes convergence properties of hyperbolic metrics.
We study maximal horizontal subgroups of Carnot groups of Heisenberg type. We classify those of dimension half of that of the canonical distribution ("lagrangians") and illustrate some notable ones of small dimension. An infinitesimal classification of the arbitrary maximal horizontal submanifolds follows as a conseque…
Paper proves unique Finsler connections for scalar forms.
problem Existence and uniqueness of Finsler connections.
method Pullback approach to global Finsler geometry, study of horizontally recurrent connections.
result Existence and uniqueness of horizontally recurrent Finsler connections for scalar forms.
The study examines constant mean curvature tubes around geodesics in specific 3-manifolds.
problem Investigating constant mean curvature surfaces in homogeneous 3-manifolds.
method Analyzing horizontal tubes foliating spaces under certain conditions.
result Horizontal tubes foliate spaces under specific curvature conditions.
Method calculates Z2-Thurston norm for Seifert 3-manifolds using pseudo-horizontal surfaces.
problem Computing Z2-Thurston norm for Z2-homology classes in orientable Seifert 3-manifolds. method Using pseudo-horizontal surfaces, we provide a necessary and sufficient criterion for their existence, calculate non-orientable genera, and develop an algorithm to compute the Z2-Thurston norm. result We successfully compute the Z2-Thurston norm for every Z2-homology class in orientable Seifert 3-manifolds. We determine necessary conditions for a non-horizontal submanifold of a sub-Riemannian stratified Lie group to be of minimal measure. We calculate the first variation of the measure for a non-horizontal submanifold and find that the minimality condition implies the tensor equation H+σ=0, where H is analogous to the…
The paper characterizes gauge balls in the Heisenberg group by their curvature.
problem Identifying level sets of gauge norm in the Heisenberg group via horizontal mean curvature.
method Establishing a uniqueness result for horizontally umbilical hypersurfaces in the Heisenberg group.
result Uniqueness result in the Heisenberg group for horizontally umbilical hypersurfaces.
Extends Masur's divergence theorem to complex tori and Kummer surfaces.
problem Establishing uniquely ergodic horizontal foliations for geodesic flows on moduli spaces.
method Defined and calculated horizontal foliations and geodesic flows on moduli spaces of Kähler metrics.
result Proved that horizontal foliations are uniquely ergodic if geodesic flows are recurrent.
We generalise a result of Garofalo and Pauls: a horizontally minimal smooth surface embedded in the Heisenberg group is locally a (straight) ruled surface, i.e. it consists of straight lines tangent to a horizontal vector field along a smooth curve. We show additionally that any horizontally minimal surface is locally …
We define and study the invariant linear and nonlinear horizontal double complexes of a local Lie group.
We show that any horizontally homothetic submersion from a compact manifold of nonnegative sectional curvature is a Riemannian submersion.
Finite intersection numbers between horizontal foliations of quadratic differentials.
problem Intersection properties of horizontal foliations in quadratic differentials.
method Joint continuity of intersection number in L1-norm. result Intersection number is finite and jointly continuous.
Horizontal surgery on pseudo-Anosov flows yields almost equivalent flows.
problem Understanding and manipulating pseudo-Anosov flows.
method Performing horizontal surgery on pseudo-Anosov flows by cutting along specific annuli and regluing with a Dehn twist.
result Horizontal Goodman surgery on transitive pseudo-Anosov flows yields an almost equivalent flow.
We find the first examples of triply periodic minimal surfaces of which the intrinsic symmetries are all of horizontal type.