Page 1 Next

Displaying 1 – 20 of 51

Showing per page

Abstract version of the Cauchy-Kowalewski problem

Oleg Zubelevich (2004)

Open Mathematics

We consider an abstract version of the Cauchy-Kowalewski Problem with the right hand side being free from the Lipschitz type conditions and prove the existence theorem.

Convergence of formal solutions of first order singular nonlinear partial differential equations in the complex domain

Masatake Miyake, Akira Shirai (2000)

Annales Polonici Mathematici

We study the convergence or divergence of formal (power series) solutions of first order nonlinear partial differential equations    (SE) f(x,u,Dx u) = 0 with u(0)=0. Here the function f(x,u,ξ) is defined and holomorphic in a neighbourhood of a point ( 0 , 0 , ξ 0 ) x n × u × ξ n ( ξ 0 = D x u ( 0 ) ) and f ( 0 , 0 , ξ 0 ) = 0 . The equation (SE) is said to be singular if f(0,0,ξ) ≡ 0 ( ξ n ) . The criterion of convergence of a formal solution u ( x ) = | α | 1 u α x α of (SE) is given by a generalized form of the Poincaré condition which depends on each formal solution. In the case where the formal...

Convergence of power series along vector fields and their commutators; a Cartan-Kähler type theorem

B. Jakubczyk (2000)

Annales Polonici Mathematici

We study convergence of formal power series along families of formal or analytic vector fields. One of our results says that if a formal power series converges along a family of vector fields, then it also converges along their commutators. Using this theorem and a result of T. Morimoto, we prove analyticity of formal solutions for a class of nonlinear singular PDEs. In the proofs we use results from control theory.

How many are affine connections with torsion

Zdeněk Dušek, Oldřich Kowalski (2014)

Archivum Mathematicum

The question how many real analytic affine connections exist locally on a smooth manifold M of dimension n is studied. The families of general affine connections with torsion and with skew-symmetric Ricci tensor, or symmetric Ricci tensor, respectively, are described in terms of the number of arbitrary functions of n variables.

How many are equiaffine connections with torsion

Zdeněk Dušek, Oldřich Kowalski (2015)

Archivum Mathematicum

The question how many real analytic equiaffine connections with arbitrary torsion exist locally on a smooth manifold M of dimension n is studied. The families of general equiaffine connections and with skew-symmetric Ricci tensor, or with symmetric Ricci tensor, respectively, are described in terms of the number of arbitrary functions of n variables.

Currently displaying 1 – 20 of 51

Page 1 Next