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On naturality of the Helmholtz operator

Włodzimierz M. Mikulski (2005)

Archivum Mathematicum

We deduce that all natural operators of the type of the Helmholtz map from the variational calculus in fibered manifolds are the constant multiples of the Helmholtz operator.

On Perelman’s functional with curvature corrections

Rami Ahmad El-Nabulsi (2012)

Annales UMCS, Mathematica

In recent ten years, there has been much concentration and increased research activities on Hamilton’s Ricci flow evolving on a Riemannian metric and Perelman’s functional. In this paper, we extend Perelman’s functional approach to include logarithmic curvature corrections induced by quantum effects. Many interesting consequences are revealed.

On principal connection like bundles

Włodzimierz M. Mikulski (2014)

Czechoslovak Mathematical Journal

Let 𝒫 m be the category of all principal fibred bundles with m -dimensional bases and their principal bundle homomorphisms covering embeddings. We introduce the concept of the so called ( r , m ) -systems and describe all gauge bundle functors on 𝒫 m of order r by means of the ( r , m ) -systems. Next we present several interesting examples of fiber product preserving gauge bundle functors on 𝒫 m of order r . Finally, we introduce the concept of product preserving ( r , m ) -systems and describe all fiber product preserving gauge...

On prolongation of connections

Włodzimierz M. Mikulski (2010)

Annales Polonici Mathematici

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 to B r . Applying...

On prolongation of higher order connections

Miroslav Doupovec, Włodzimierz M. Mikulski (2011)

Annales Polonici Mathematici

We describe all bundle functors G admitting natural operators transforming rth order holonomic connections on a fibered manifold Y → M into rth order holonomic connections on GY → M. For second order holonomic connections we classify all such natural operators.

On prolongations of projectable connections

Jan Kurek, Włodzimierz M. Mikulski (2011)

Annales Polonici Mathematici

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 (r,r,r)-order...

On skew 2-projectable almost complex structures on T M

Anton Dekrét (1998)

Archivum Mathematicum

We deal with a ( 1 , 1 ) -tensor field α on the tangent bundle T M preserving vertical vectors and such that J α = - α J is a ( 1 , 1 ) -tensor field on M , where J is the canonical almost tangent structure on T M . A connection Γ α on T M is constructed by α . It is shown that if α is a V B -almost complex structure on T M without torsion then Γ α is a unique linear symmetric connection such that α ( Γ α ) = Γ α and Γ α ( J α ) = 0 .

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