This paper constructs a family of coordinate systems about a point on a quaternionic contact manifold, called quaternionic contact pseudohermitian normal coordinates. Once defined, conformal variations of the quaternionic contact structure induce changes on the coordinates which are studied in an effort to simplify the…
Normalizes pseudo-Einstein contact forms for easier analysis.
problem Understanding pseudo-Einstein contact forms.
method Constructing intrinsic CR normal coordinates using parabolic normal coordinates.
result Normal form for pseudo-Einstein contact forms.
Let $\CV$ be a vector field distribution on manifold M. We give an efficient algorithm for the construction of local coordinates on M such that $\CV$ may be locally expressed as some partial prolongation of the contact distribution $\Cal C^{(1)}_q$, on the first order jet bundle of maps from R to Rq,…
We present a compared analysis of some properties of 3-Sasakian and 3-cosymplectic manifolds. We construct a canonical connection on an almost 3-contact metric manifold which generalises the Tanaka-Webster connection of a contact metric manifold and we use this connection to show that a 3-Sasakian manifold does not adm…
Study finds lowest-degree invariant PDEs over rational contact manifolds.
problem Finding the simplest invariant PDEs over rational contact manifolds.
method Analyzes simple Lie algebras to find lowest-degree invariant second-order PDEs.
result Provides explicit formulas and proves uniqueness for specific types of Lie algebras.
Geometric study of thermodynamics using cotangent bundles.
problem Formulating classical thermodynamics using geometric structures.
method Contact geometry on cotangent bundles, homogeneous coordinates for intensive variables.
result Geometric formulation of thermodynamics with homogeneity properties.
Contact Riemannian manifolds, whose complex structures are not necessarily integrable, are generalization of pseudohermitian manifolds in CR geometry. The Tanaka-Webster-Tanno connection plays the role of the Tanaka-Webster connection of a pseudohermitian manifold. Conformal transformations and the Yamabe problem are a…
The study explores autonomous systems and their connections to contact geometry and Frobenius manifolds.
problem Understanding the connections between autonomous systems and geometric structures.
method Investigation of the Darboux-Halphen-Ramanujan system, contact geometry, and Frobenius manifolds.
result Highlighting the role of contact geometry in autonomous systems.
New geometric framework for non-conservative field theories with time-dependent terms.
problem Describing non-conservative field theories with explicit space-time dependence.
method Combining k-cosymplectic and k-contact formulations to develop Hamiltonian and Lagrangian formalisms.
result Illustrated with the nonlinear damped wave equation, demonstrating the new formalism's applicability.
Jet bundles as higher-order polarised k-contact manifolds
problem Recognizing finite-order jet bundles as polarised Nπr-contact manifolds method Introducing new classes of polarisations for k-contact distributions result Main recognition theorem
Torus knots (4,5) and (5,6) provide counterexamples to a conjecture about knot contact homology.
problem Ng's conjecture about isomorphism between knot contact homology and character variety fails for certain torus knots.
method Demonstrated through the construction of ghost characters for specific torus knots.
result Counterexamples to Ng's conjecture for (4,5) and (5,6) torus knots. Study knot contact homology and character varieties to prove a conjecture about knots.
problem Relate knot contact homology to character varieties of branched covers.
method Study trace-free characters of knot groups and their connection to character varieties.
result Prove Ng's conjecture for 2-bridge and 3-bridge knots using ghost characters.
Develop contact Tulczyjew formalism for dissipative dynamics on skew algebroids.
problem Dissipative dynamics on skew algebroids
method Contact Tulczyjew formalism
result Intrinsic explanation of contact term and Euler-Lagrange-Herglotz equations
The paper introduces Carnot coordinates for Carnot manifolds, simplifying nilpotent approximation.
problem Nilpotent approximation of Carnot manifolds.
method Identification of Carnot coordinates as privileged coordinates with specific properties.
result Carnot coordinates provide a precise and effective nilpotent approximation of Carnot manifolds.
A new metriplectic system on contact manifolds is introduced for thermodynamic consistency.
problem Developing a thermodynamically consistent dynamical system on contact manifolds.
method Introducing a metriplectic dynamical system on the one-jet bundle J1N. result The metriplectic system is thermodynamically consistent, with H˙=0 and S˙≥0. Study of contact whirl curves in Sasakian Lorentzian 3-manifolds.
problem Understanding the geometric properties of curves in Lorentzian contact manifolds.
method Introducing and analyzing contact whirl curves, deriving differential equations, and proving rigidity phenomena.
result Every non-geodesic Legendre Frenet curve is a contact whirl curve with constant torsion τ=1.
Let M be a three-dimensional contact manifold and ψ:D∖{0}→M×R a finite-energy pseudoholomorphic map from a punctured disc in C, that is asymptotic to a periodic orbit of the Reeb vector field. This article examines conditions under which smooth coordinates may be defined in a tubul…
Cyclidic nets are introduced as discrete analogs of curvature line parametrized surfaces and orthogonal coordinate systems. A 2-dimensional cyclidic net is a piecewise smooth C1-surface built from surface patches of Dupin cyclides, each patch being bounded by curvature lines of the supporting cyclide. An explicit de…
I define higher codimensional versions of contact structures on manifolds as maximally non-integrable distributions. I call them multicontact structures. Cartan distributions on jet spaces provide canonical examples. More generally, I define higher codimensional versions of pre-contact structures as distributions on ma…
Equivalence of conformal maps proved in sub-Riemannian manifolds.
problem Equivalence of conformal maps between sub-Riemannian manifolds.
method Regularity theory for subelliptic p-Laplacian operators, sub-Riemannian p-harmonic coordinates, propagation of regularity.
result 1-quasiconformal maps are smooth on contact manifolds.
Locally symplectic structure found on Kerr space-time.
problem Understanding Kerr space-time using geodesics.
method Identifying locally conformally symplectic structure using characteristic classes and Kerr-Schild coordinates.
result Definition of cobordism category of contact 3-manifolds and locally conformally symplectic cobordisms.
We provide necessary and sufficient conditions on the derived type of a vector field distribution $\Cal V$ in order that it be locally equivalent to a partial prolongation of the contact distribution $\Cal C^{(1)}_q$, on the first order jet bundle of maps from R to Rq, q≥1. This result fully genera…
In the same way that a contact manifold determines and is determined by a symplectic cone, a Sasaki manifold determines and is determined by a suitable Kahler cone. Kahler-Sasaki geometry is the geometry of these cones. This paper presents a symplectic action-angle coordinates approach to toric Kahler geometry and how …
This research extends Sasakian geometry to non-necessarily coorientable contact structures.
problem Extending Sasakian geometry to non-necessarily coorientable contact structures.
method Homogeneous Kähler structures on principal Rimes-bundles. result Characterizes the extent of generalization from Sasakian to homogeneous Kähler structures.
Survey article analyzes pseudoholomorphic curves on symplectization via contact instantons.
problem Analyzing pseudoholomorphic curves on symplectization.
method Using contact instantons and a coordinate-free covariant tensorial calculus.
result Stronger and more accurate a priori estimates for pseudoholomorphic curves.
Study null geodesics on specific spacetimes, finding contact manifolds and Engel geometry applications.
problem Computing the space of null geodesics for a family of spacetimes.
method Computed the contact manifold of null geodesics for a specific family of spacetimes using Engel geometry.
result Characterized the contact manifolds of null geodesics and retrieved the spacetime.
We investigate the number of geodesics between two points p and q on a contact sub-Riemannian manifold M. We show that the count of geodesics on M is controlled by the count on its nilpotent approximation at p (a contact Carnot group). For contact Carnot groups we make the count explicit in exponential coordina…
For curved projective manifolds we introduce a notion of a normal tractor frame field, based around any point. This leads to canonical systems of (redundant) coordinates that generalise the usual homogeneous coordinates on projective space. These give preferred local maps to the model projective space that encode geome…
Elie Cartan's general equivalence problem is recast in the language of Lie algebroids. The resulting formalism, being coordinate and model-free, allows for a full geometric interpretation of Cartan's method of equivalence via reduction and prolongation. We show how to construct certain normal forms (Cartan algebroids) …
Paper tackles dynamic behavior of variable topology mechanisms, presenting new transition conditions.
problem Dynamic behavior of mechanisms with changing kinematic topology.
method Presented new transition conditions for variable topology mechanisms using projected motion equations and Voronets equations.
result Results show the dynamic behavior of joint locking in 3R and 6DOF mechanisms.
Unified geometric framework for integrability of conservative and dissipative systems.
problem Unified definition of integrability for both conservative and dissipative systems.
method Introducing Jacobi-Haantjes manifolds and contact-Haantjes manifolds to unify definitions.
result Equivalence of integrability in contact Hamiltonian systems and existence of Abelian extended Haantjes algebra.
A new geometric approach to quantum mechanics simplifies time-dependent problems.
problem Quantum mechanics ambiguities in time and observer choices.
method Generally covariant phase-spacetime coordinates and geometric flatness condition.
result Quantum mechanics becomes purely geometric and potentially topological.
In the paper we develop a framework for the alternative way of the study of a local geometry of almost cosymplectic manifolds with Kahlerian leaves. The main idea is to apply the concept of a geometry and analysis of CR manifolds. Locally the almost cosymplectic manifold is modeled on the 'mixed' space RxCn. There is g…
Classifies homogeneous Pfaffian forms on graded manifolds.
problem Local classification of homogeneous Pfaffian forms on graded manifolds.
method Darboux coordinates and characteristic distribution analysis.
result Darboux-type normal forms for homogeneous Pfaffian forms.
Principal binets generalize curvature line surfaces to square lattices and are a discrete integrable system.
problem Discretizing curvature line surfaces on square lattices.
method Showed principal binets as a multi-dimensional consistent system.
result Principal binets generalize to higher-dimensional square lattices and are integrable.
As a step toward proving an index theorem for hypoelliptic operators Heisenberg manifolds, including those on CR and contact manifolds, we construct an analogue for Heisenberg manifolds of Connes' tangent groupoid of a manifold M. As it is well known for a Heisenberg manifold (M,H) the relevant notion of tangent is…
We consider the space of differential operators Dλμ acting between λ- and μ-densities defined on S1∣2 endowed with its standard contact structure. This contact structure allows one to define a filtration on Dλμ which is finer than the classical one, obtained by writting a differen…
Corrected Monti's blow-up analysis for H-minimizing sets in Heisenberg group.
problem Blow-up analysis of H-minimizing sets in Heisenberg group with corrected partial differential equation.
method Revised Monti's results on blow-ups of H-perimeter minimizing sets in Hn and corrected the partial differential equation for the limit function. result Corrected the partial differential equation for the limit function of blow-ups in Heisenberg group.
This paper applies differential algebra to study equations in mathematical physics.
problem Equations in mathematical physics often involve derivatives of functions.
method Uses differential algebra, differential geometry, and algebraic analysis to study equations.
result Linearized second order Einstein equations cannot be parametrized.
Research finds double bubbles in Grushin plane with specific geometric properties.
problem Addressing double bubble problem in Grushin plane with anisotropic perimeter.
method Existence via direct method and characterization via first variation techniques.
result Angles at intersections satisfy 120-degree rule, with differences for α=0 and α=1.
New examples show contact structures can be isotopic but not contact-isotopic.
problem Identifying contact structures that are isotopic but not contact-isotopic.
method Constructing specific contactomorphisms in all dimensions.
result Infinitely many examples of contactomorphisms that are isotopic but not contact-isotopic.
The study explores embedding closed contact manifolds in higher dimensions.
problem Iso-contact embeddings of closed contact manifolds in co-dimension 2.
method Analyzes conditions for iso-contact embeddings and applies results to specific cases.
result Closed contact 3-manifolds without 2-torsion in their cohomology iso-contact embed in the standard contact 5-sphere.
Study on contact Hamiltonian functions for singular contact structures.
problem Understanding infinitesimal contact transformations on singular contact structures.
method Showed injectivity and provided an explicit local formula for the inverse map.
result Explicit local formula for the inverse map when contact structure has singularities of the first type.
Contact round surgery proves existence of contact structures on 3-manifolds.
problem Existence of contact structures on 3-manifolds.
method Contact round surgery and Lutz twist/Giroux torsion operations.
result Any contact structure on a closed orientable 3-manifold is constructed from the standard contact structure on the 3-sphere via contact round surgeries.
The paper defines and studies contact surgery numbers for contact 3-manifolds.
problem Understanding the minimal number of components of a surgery link describing a contact 3-manifold.
method Defined and studied various versions of contact surgery numbers, relating them to other invariants and computing specific cases.
result There exist infinitely many non-isotopic contact structures on certain manifolds that cannot be obtained by a single rational contact surgery from the standard tight contact 3-sphere.
Study weak quasi contact metric manifolds to generalize K-contact and Sasakian manifolds criteria.
problem Generalize K-contact and Sasakian manifolds criteria using weak quasi contact metric manifolds.
method Study weak quasi contact metric manifolds and generalize theorems for K-contact and Sasakian manifolds.
result Provide new criterions for K-contact and Sasakian manifolds in terms of curvature tensor and geometric objects.
Simplified construction of contact triad connection for analysis.
problem Analyzing contact instanton equation on contact triads.
method Characterization via almost contact structure and construction using almost contact moving frame.
result Simpler and more canonical construction of contact triad connection.
The paper examines conditions for contact surgeries on rational homology 3-spheres.
problem Conditions for contact surgeries on rational homology 3-spheres.
method Analyzes sufficient conditions for contact surgeries using Legendrian knots and links.
result Provides sufficient conditions for surgeries to have vanishing contact invariants or to be overtwisted.