Results 11 to 20 of about 13,251 (150)
Precision planter monitoring system based on mobile communication network
IET Networks, EarlyView., 2022 Abstract Sowing is an important link in agricultural production and the basis for ensuring high yields and bumper harvests. Agriculture requires precision plows with good performance and stable work. However, the seeding process is in a completely closed state, and the operator relies mainly on experience to judge the operating state and performance of
Bing Li, Jiyun Li
wiley +1 more source
Metric projective geometry, BGG detour complexes and partially massless gauge theories [PDF]
, 2014 A projective geometry is an equivalence class of torsion free connections sharing the same unparametrised geodesics; this is a basic structure for understanding physical systems.
Gover, A. R., Latini, E., Waldron, A.
core +3 more sources
Symmetry, Integrability and Geometry: Methods and ApplicationsThis article contributes to the relative BGG-machinery for parabolic geometries. Starting from a relative tractor bundle, this machinery constructs a sequence of differential operators that are naturally associated to the geometry in question. In many situations of interest, it is known that this sequence provides a resolution of a sheaf that can ...
Čap, Andreas +2 more
openaire +5 more sources
Conformal superalgebras via tractor calculus [PDF]
, 2014 We use the manifestly conformally invariant description of a Lorentzian conformal structure in terms of a parabolic Cartan geometry in order to introduce a superalgebra structure on the space of twistor spinors and normal conformal vector fields ...
Lischewski, Andree
core +1 more source
CR-Tractors and the Fefferman Space
, 2008 We develop the natural tractor calculi associated to conformal and CR structures as a fundamental tool for the study of Fefferman's construction of a canonical conformal class on the total space of a circle bundle over a non--degenerate CR manifold of ...
Cap, Andreas, Gover, A. Rod
core +2 more sources
Calculus on symplectic manifolds [PDF]
, 2008 On a symplectic manifold, there is a natural elliptic complex replacing the de Rham complex. It can be coupled to a vector bundle with connection and, when the curvature of this connection is constrained to be a multiple of the symplectic form, we find a
Eastwood, Michael, Slovak, Jan
core +6 more sources
Conformally Invariant Operators via Curved Casimirs: Examples
, 2009 We discuss a general scheme for a construction of linear conformally invariant differential operators from curved Casimir operators; we then explicitly carry this out for several examples.
Cap, Andreas +2 more
core +1 more source
Conformal and projective tractors from 2-frame bundles by the dressing field method
International Journal of Geometric Methods in Modern PhysicsThis paper is devoted to the study of conformal and projective structures, and especially their connections, in the language of 2-frames, or [Formula: see text]-structures of second order. While their normal Cartan connections are well-known, we use the dressing field method to obtain their local, mostly gauge invariant, connections. Lastly, we recall
L. Marsot, S. Lazzarini
openaire +4 more sources
Holonomy reductions of Cartan geometries and curved orbit decompositions
, 2014 We develop a holonomy reduction procedure for general Cartan geometries. We show that, given a reduction of holonomy, the underlying manifold naturally decomposes into a disjoint union of initial submanifolds.
Cap, Andreas +2 more
core +1 more source
Twistor Geometry of Null Foliations in Complex Euclidean Space [PDF]
, 2017 We give a detailed account of the geometric correspondence between a smooth complex projective quadric hypersurface $\mathcal{Q}^n$ of dimension $n \geq 3$, and its twistor space $\mathbb{PT}$, defined to be the space of all linear subspaces of maximal ...
Taghavi-Chabert, Arman
core +3 more sources