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Publications Influence

Ultrastructural and chemical changes in the cell wall of Haematococcus pluvialis (Volvocales, Chlorophyta) during aplanospore formation

- Christoph Hagen, S. Siegmund, W. Braune
- Biology
- 29 April 2002

Changes in the ultrastructure and chemistry of the cell wall of the unicellular volvocalean green alga Haematococcus pluvialis were investigated during the transformation of flagellates into… Expand

142 16

A spectral characterization of exponential stability for linear time-invariant systems on time scales

- C. Pötzsche, S. Siegmund, F. Wirth
- Mathematics
- 1 June 2003

We prove a necessary and sufficient condition for the exponential
stability of time-invariant linear systems on time scales in terms of
the eigenvalues of the system matrix. In particular, this… Expand

111 10

The dichotomy spectrum for noninvertible systems of linear difference equations

- B. Aulbach, S. Siegmund
- Mathematics
- 2001

In this paper we introduce the so—called dichotomy spectrum for nonautonomous linear difference equations , whose coefficient matrices are not supposed to be invertible. This new kind of spectrum i...

56 5

Hyperbolicity and Invariant Manifolds for Planar nonautonomous Systems on Finite Time Intervals

- Luu Hoang Duc, S. Siegmund
- Mathematics, Computer Science
- Int. J. Bifurc. Chaos
- 1 March 2008

TLDR

34 3- PDF

Invariant manifolds as pullback attractors of nonautonomous differential equations

- B. Aulbach, M. Rasmussen, S. Siegmund
- Mathematics
- 1 March 2006

We discuss the relationship between invariant manifolds of
nonautonomous differential equations and pullback attractors. This
relationship is essential, e.g., for the numerical approximation
of… Expand

21 3- PDF

Dichotomy Spectrum for Nonautonomous Differential Equations

- S. Siegmund
- Mathematics
- 2002

For nonautonomous linear differential equations ⋅x=A(t) x with locally integrable A: R→RN×N the so-called dichotomy spectrum is investigated in this paper. As the closely related dichotomy spectrum… Expand

63 3- PDF

A definition of spectrum for differential equations on finite time

- A. Berger, T. Doan, S. Siegmund
- Mathematics
- 1 February 2009

Abstract Hyperbolicity of an autonomous rest point is characterised by its linearization not having eigenvalues on the imaginary axis. More generally, hyperbolicity of any solution which exists for… Expand

24 3- PDF

Nonuniform dichotomy spectrum and reducibility for nonautonomous equations

- J. Chu, F. Liao, S. Siegmund, Yonghui Xia, W. Zhang
- Mathematics
- 10 February 2014

Abstract For nonautonomous linear differential equations with nonuniform hyperbolicity, we introduce a definition for nonuniform dichotomy spectrum, which can be seen as a generalization of… Expand

12 3- PDF

POSITIVE PERIODIC SOLUTIONS FOR THIRD-ORDER NONLINEAR DIFFERENTIAL EQUATIONS

- J. Ren, S. Siegmund, Yueli Chen
- Mathematics
- 18 May 2011

For several classes of third-order constant coefficient linear differential equations we obtain existence and uniqueness of periodic solutions utilizing explicit Green';s functions. We discuss an… Expand

13 3

Exponential Stability of Linear Time-Invariant Systems on Time Scales

- Anke Kalauch, S. Siegmund
- Mathematics
- 2009

Several notions of exponential stability of linear time-invariant sys- tems on arbitrary time scales are discussed. We establish a necessary and suffi- cient condition for the existence of uniform… Expand

21 2- PDF