Displaying similar documents to “Horizontal lift of symmetric connections to the bundle of volume forms 𝒱

Constructions on second order connections

J. Kurek, W. M. Mikulski (2007)

Annales Polonici Mathematici

Similarity:

We classify all m , n -natural operators : J ² J ² V A transforming second order connections Γ: Y → J²Y on a fibred manifold Y → M into second order connections ( Γ ) : V A Y J ² V A Y on the vertical Weil bundle V A Y M corresponding to a Weil algebra A.

On prolongations of projectable connections

Jan Kurek, Włodzimierz M. Mikulski (2011)

Annales Polonici Mathematici

Similarity:

We extend the concept of r-order connections on fibred manifolds to the one of (r,s,q)-order projectable connections on fibred-fibred manifolds, where r,s,q are arbitrary non-negative integers with s ≥ r ≤ q. Similarly to the fibred manifold case, given a bundle functor F of order r on (m₁,m₂,n₁,n₂)-dimensional fibred-fibred manifolds Y → M, we construct a general connection ℱ(Γ,Λ):FY → J¹FY on FY → M from a projectable general (i.e. (1,1,1)-order) connection Γ : Y J 1 , 1 , 1 Y on Y → M by means of an...

Liftings of 1-forms to ( J r T * ) *

Włodzimierz M. Mikulski (2002)

Colloquium Mathematicae

Similarity:

Let J r T * M be the r-jet prolongation of the cotangent bundle of an n-dimensional manifold M and let ( J r T * M ) * be the dual vector bundle. For natural numbers r and n, a complete classification of all linear natural operators lifting 1-forms from M to 1-forms on ( J r T * M ) * is given.

Singer-Thorpe bases for special Einstein curvature tensors in dimension 4

Zdeněk Dušek (2015)

Czechoslovak Mathematical Journal

Similarity:

Let ( M , g ) be a 4-dimensional Einstein Riemannian manifold. At each point p of M , the tangent space admits a so-called Singer-Thorpe basis (ST basis) with respect to the curvature tensor R at p . In this basis, up to standard symmetries and antisymmetries, just 5 components of the curvature tensor R are nonzero. For the space of constant curvature, the group O ( 4 ) acts as a transformation group between ST bases at T p M and for the so-called 2-stein curvature tensors, the group Sp ( 1 ) SO ( 4 ) acts as a transformation...

On lifting of connections to Weil bundles

Jan Kurek, Włodzimierz M. Mikulski (2012)

Annales Polonici Mathematici

Similarity:

We prove that the problem of finding all f m -natural operators B : Q Q T A lifting classical linear connections ∇ on m-manifolds M to classical linear connections B M ( ) on the Weil bundle T A M corresponding to a p-dimensional (over ℝ) Weil algebra A is equivalent to the one of finding all f m -natural operators C : Q ( T ¹ p - 1 , T * T * T ) transforming classical linear connections ∇ on m-manifolds M into base-preserving fibred maps C M ( ) : T ¹ p - 1 M = M p - 1 T M T * M T * M T M .

Linear natural operators lifting p -vectors to tensors of type ( q , 0 ) on Weil bundles

Jacek Dębecki (2016)

Czechoslovak Mathematical Journal

Similarity:

We give a classification of all linear natural operators transforming p -vectors (i.e., skew-symmetric tensor fields of type ( p , 0 ) ) on n -dimensional manifolds M to tensor fields of type ( q , 0 ) on T A M , where T A is a Weil bundle, under the condition that p 1 , n p and n q . The main result of the paper states that, roughly speaking, each linear natural operator lifting p -vectors to tensor fields of type ( q , 0 ) on T A is a sum of operators obtained by permuting the indices of the tensor products of linear natural...

On canonical constructions on connections

Jan Kurek, Włodzimierz Mikulski (2016)

Annales Universitatis Mariae Curie-Sklodowska, sectio A – Mathematica

Similarity:

We study  how a projectable general connection Γ in a 2-fibred manifold Y 2 Y 1 Y 0   and a general vertical connection Θ in Y 2 Y 1 Y 0 induce a general connection A ( Γ , Θ ) in Y 2 Y 1 .

Lifting right-invariant vector fields and prolongation of connections

W. M. Mikulski (2009)

Annales Polonici Mathematici

Similarity:

We describe all m ( G ) -gauge-natural operators lifting right-invariant vector fields X on principal G-bundles P → M with m-dimensional bases into vector fields (X) on the rth order principal prolongation W r P = P r M × M J r P of P → M. In other words, we classify all m ( G ) -natural transformations J r L P × M W r P T W r P = L W r P × M W r P covering the identity of W r P , where J r L P is the r-jet prolongation of the Lie algebroid LP=TP/G of P, i.e. we find all m ( G ) -natural transformations which are similar to the Kumpera-Spencer isomorphism J r L P = L W r P . We formulate axioms which...

Lifting to the r-frame bundle by means of connections

J. Kurek, W. M. Mikulski (2010)

Annales Polonici Mathematici

Similarity:

Let m and r be natural numbers and let P r : f m be the rth order frame bundle functor. Let F : f m and G : f k be natural bundles, where k = d i m ( P r m ) . We describe all f m -natural operators A transforming sections σ of F M M and classical linear connections ∇ on M into sections A(σ,∇) of G ( P r M ) P r M . We apply this general classification result to many important natural bundles F and G and obtain many particular classifications.

On prolongation of connections

Włodzimierz M. Mikulski (2010)

Annales Polonici Mathematici

Similarity:

Let Y → M be a fibred manifold with m-dimensional base and n-dimensional fibres. Let r, m,n be positive integers. We present a construction B r of rth order holonomic connections B r ( Γ , ) : Y J r Y on Y → M from general connections Γ:Y → J¹Y on Y → M by means of torsion free classical linear connections ∇ on M. Then we prove that any construction B of rth order holonomic connections B ( Γ , ) : Y J r Y on Y → M from general connections Γ:Y → J¹Y on Y → M by means of torsion free classical linear connections ∇ on M is equal...

Shells of monotone curves

Josef Mikeš, Karl Strambach (2015)

Czechoslovak Mathematical Journal

Similarity:

We determine in n the form of curves C corresponding to strictly monotone functions as well as the components of affine connections for which any image of C under a compact-free group Ω of affinities containing the translation group is a geodesic with respect to . Special attention is paid to the case that Ω contains many dilatations or that C is a curve in 3 . If C is a curve in 3 and Ω is the translation group then we calculate not only the components of the curvature and the Weyl...

On the γ -equivalence of semiholonomic jets

Miroslav Doupovec, Ivan Kolář (2019)

Archivum Mathematicum

Similarity:

It is well known that the concept of holonomic r -jet can be geometrically characterized in terms of the contact of individual curves. However, this is not true for the semiholonomic r -jets, [5], [8]. In the present paper, we discuss systematically the semiholonomic case.

Structure of second-order symmetric Lorentzian manifolds

Oihane F. Blanco, Miguel Sánchez, José M. Senovilla (2013)

Journal of the European Mathematical Society

Similarity:

𝑆𝑒𝑐𝑜𝑛𝑑 - 𝑜𝑟𝑑𝑒𝑟𝑠𝑦𝑚𝑚𝑒𝑡𝑟𝑖𝑐𝐿𝑜𝑟𝑒𝑛𝑡𝑧𝑖𝑎𝑛𝑠𝑝𝑎𝑐𝑒𝑠 , that is to say, Lorentzian manifolds with vanishing second derivative R 0 of the curvature tensor R , are characterized by several geometric properties, and explicitly presented. Locally, they are a product M = M 1 × M 2 where each factor is uniquely determined as follows: M 2 is a Riemannian symmetric space and M 1 is either a constant-curvature Lorentzian space or a definite type of plane wave generalizing the Cahen–Wallach family. In the proper case (i.e., R 0 at some point), the curvature...

On lifts of projectable-projectable classical linear connections to the cotangent bundle

Anna Bednarska (2013)

Annales Universitatis Mariae Curie-Sklodowska, sectio A – Mathematica

Similarity:

We describe all 2 m 1 , m 2 , n 1 , n 2 -natural operators D : Q p r o j - p r o j τ Q T * transforming projectable-projectable classical torsion-free linear connections on fibred-fibred manifolds Y into classical linear connections D ( ) on cotangent bundles T * Y of Y . We show that this problem can be reduced to finding 2 m 1 , m 2 , n 1 , n 2 -natural operators D : Q p r o j - p r o j τ ( T * , p T * q T ) for p = 2 , q = 1 and p = 3 , q = 0 .

The vertical prolongation of the projectable connections

Anna Bednarska (2012)

Annales Universitatis Mariae Curie-Sklodowska, sectio A – Mathematica

Similarity:

We prove that any first order 2 m 1 , m 2 , n 1 , n 2 -natural operator transforming projectable general connections on an ( m 1 , m 2 , n 1 , n 2 ) -dimensional fibred-fibred manifold p = ( p , p ) : ( p Y : Y Y ) ( p M : M M ) into general connections on the vertical prolongation V Y M of p : Y M is the restriction of the (rather well-known) vertical prolongation operator 𝒱 lifting general connections Γ ¯ on a fibred manifold Y M into 𝒱 Γ ¯ (the vertical prolongation of Γ ¯ ) on V Y M .

Two-dimensional curvature functionals with superquadratic growth

Ernst Kuwert, Tobias Lamm, Yuxiang Li (2015)

Journal of the European Mathematical Society

Similarity:

For two-dimensional, immersed closed surfaces f : Σ n , we study the curvature functionals p ( f ) and 𝒲 p ( f ) with integrands ( 1 + | A | 2 ) p / 2 and ( 1 + | H | 2 ) p / 2 , respectively. Here A is the second fundamental form, H is the mean curvature and we assume p > 2 . Our main result asserts that W 2 , p critical points are smooth in both cases. We also prove a compactness theorem for 𝒲 p -bounded sequences. In the case of p this is just Langer’s theorem [16], while for 𝒲 p we have to impose a bound for the Willmore energy strictly below 8 π as an additional...

The natural transformations between r-tangent and r-cotangent bundles over Riemannian manifolds

Jan Kurek, Włodzimierz Mikulski (2014)

Annales Universitatis Mariae Curie-Sklodowska, sectio A – Mathematica

Similarity:

If ( M , g ) is a Riemannian manifold, we have the well-known base preserving   vector bundle isomorphism T M = ˜ T * M given by v g ( v , - ) between the tangent T M and the cotangent T * M bundles of M . In the present note, we generalize this isomorphism to the one T ( r ) M = ˜ T r * M between the r -th order vector tangent T ( r ) M = ( J r ( M , R ) 0 ) * and the r -th order cotangent T r * M = J r ( M , R ) 0 bundles of M . Next, we describe all base preserving  vector bundle maps C M ( g ) : T ( r ) M T r * M depending on a Riemannian metric g in terms of natural (in g ) tensor fields on M .

Lagrangians and Euler morphisms on fibered-fibered frame bundles from projectable-projectable classical linear connections

Anna Bednarska (2011)

Annales Universitatis Mariae Curie-Sklodowska, sectio A – Mathematica

Similarity:

We classify all 2 m 1 , m 2 , n 1 , n 2 -natural operators A transforming projectable-projectable torsion-free classical linear connections on fibered-fibered manifolds Y of dimension ( m 1 , m 2 , n 1 , n 2 ) into r th order Lagrangians A ( r ) on the fibered-fibered linear frame bundle L f i b - f i b ( Y ) on Y . Moreover, we classify all 2 m 1 , m 2 , n 1 , n 2 -natural operators B transforming projectable-projectable torsion-free classical linear connections r on fiberedfibered manifolds Y of dimension  ( m 1 , m 2 , n 1 , n 2 ) into Euler morphism B ( ) on L f i b - f i b ( Y ) . These classifications can be expanded on...

Geometric stability of the cotangent bundle and the universal cover of a projective manifold

Frédéric Campana, Thomas Peternell (2011)

Bulletin de la Société Mathématique de France

Similarity:

We first prove a strengthening of Miyaoka’s generic semi-positivity theorem: the quotients of the tensor powers of the cotangent bundle of a non-uniruled complex projective manifold X have a pseudo-effective (instead of generically nef) determinant. A first consequence is that X is of general type if its cotangent bundle contains a subsheaf with ‘big’ determinant. Among other applications, we deduce that if the universal cover of X is not covered by compact positive-dimensional analytic...