Remark on Wielandt's visibility theorem

A note on the Hoffman-Wielandt theorem

✍ L. Elsner 📂 Article 📅 1993 🏛 Elsevier Science 🌐 English ⚖ 129 KB

A Remark on Goldschmidt's Theorem on For

A Remark on Goldschmidt's Theorem on Formal Integrability

✍ J. Muñoz; F.J. Muriel; J. Rodrı́guez 📂 Article 📅 2001 🏛 Elsevier Science 🌐 English ⚖ 137 KB

In this paper we apply Weil bundle techniques to the study of formal integrability for systems of nonlinear partial differential equations. We clarify the role of the curvature and show that both the statement and proof of Goldschmidt's criterion on formal integrability are of algebraic nature. This

On Jacobi's remarkable curve theorem

✍ John McCleary 📂 Article 📅 1994 🏛 Elsevier Science 🌐 English ⚖ 439 KB

## FOR DIRK STRUIK ON HIS |00TH BIRTHDAY One of the prettiest results in the global theory of curves is a theorem of Jacobi (1842): The spherical image of the normal directions along a closed differentiable curve in space divides the unit sphere into regions of equal area. The statement of this t

Two remarks on Ramsey's theorem

✍ Jaroslav Nes̆etr̆il; Vojtĕch Rödl 📂 Article 📅 1985 🏛 Elsevier Science 🌐 English ⚖ 131 KB

We present a very simple proof of the fact (due to P. Erd~s and R. Rado) that Ram~ey's theorem doesn't hold for partitions of infinite subsets. We also present a proof of an induced Ramsey theorem for partitions of complete subgraphs (due to W. Deuber and authors) based on the theorem of R. Graham a

Some remarks on Bernstein's theorems

✍ Adam P Wójcik 📂 Article 📅 1991 🏛 Elsevier Science 🌐 English ⚖ 937 KB

Remark on the Hopf Bifurcation Theorem

✍ A. M. Krasnosel'skii; D. I. Rachinskii 📂 Article 📅 2004 🏛 John Wiley and Sons 🌐 English ⚖ 164 KB

## Abstract A simple generalization of the Hopf Bifurcation Theorem for scalar higher order ordinary differential equations is suggested. We study the degenerate case where several roots of the characteristic polynomial cross the imaginary axis at the same point for some value __λ__~0~ of the param