Publikationen

2022

J. Chu, F.-F. Liao, S. Siegmund, Y. Xia, H. Zhu.
Nonuniform dichotomy spectrum and reducibility for nonautonomous difference equations.
Advances in Nonlinear Analysis 11 (2022), 369-384.

2021

K. Diethelm, K. Kitzing, R. Picard, S. Siegmund, S. Trostorff, M. Waurick.
A Hilbert space approach to fractional differential equations.
Journal of Dynamics and Differential Equations (2021), doi.org/10.1007/s10884-020-09932-6.

A. Babiarz, A. Czornik, S. Siegmund.
On stabilization of discrete time-varying systems.
SIAM Journal on Control and Optimization 59 (2021), 242-266.

2020

P.T. Anh, A. Babiarz, A. Czornik, K. Kitzing, M. Niezabitowski, S. Siegmund, S. Trostorff, H.T. Tuan.
A Hilbert Space Approach to Fractional Difference Equations.
Springer Proceedings in Mathematics & Statistics, vol 312. Springer, Cham, 2020. doi:10.1007/978-3-030-35502-9_4.

S. Siegmund, P. Stehlík.
Time scale-induced asynchronous discrete dynamical systems.
Discrete & Continuous Dynamical Systems - B 22 (2020), doi:10.3934/dcdsb.2020151.

Hoang The Tuan, S. Siegmund.
Stability of scalar nonlinear fractional differential equations with linearly dominated delay.
Fractional Calculus and Applied Analysis 23 (2020), 250-267.

Pham The Anh, A. Babiarz, A. Czornik, M. Niezabitowski, S. Siegmund.
Some results on linear nabla Riemann-Liouville fractional difference equations.
Mathematical Methods in the Applied Sciences 43 (2020), 7815-7824.

2019

Pham The Anh, A. Babiarz, A. Czornik, M. Niezabitowski, S. Siegmund.
On asymptotic properties of discrete Volterra equations of convolution type.
2019 24th International Conference on Methods and Models in Automation and Robotics (MMAR), Międzyzdroje, Poland, 2019, pp. 13-17.

S. Piskarev, S. Siegmund.
Approximations of stable manifolds in the vicinity of hyperbolic equilibrium points for fractional differential equations.
Nonlinear Dynamics 95:1 (2019), 685-697.

Pham The Anh, A. Babiarz, A. Czornik, M. Niezabitowski, S. Siegmund.
Asymptotic properties of discrete linear fractional equations.
Bulletin of the Polish Academy of Sciences: Technical Sciences, Volume 67, Issue 4 (2019), 749-759.

L.V. Cuong, T.S. Doan, S. Siegmund.
A Sternberg theorem for nonautonomous differential equations.
Journal of Dynamics and Differential Equations 31 (2019), 1279-1299.

Pham The Anh, P. Jurgás, M. Niezabitowski, S. Siegmund.
Variation of constant formulas of linear autonomous Grünwald-Letnikov-type fractional difference equations.
AIP Conference Proceedings, Volume 2116, Issue 1 (July 2019), id.450082, doi:10.1063/1.5114549.

2014-2018

P.T. Anh, A. Babiarz, A. Czornik, M. Niezabitowski, S. Siegmund.
Variation of constant formulas for fractional difference equations.
Archives of Control Sciences 28:4 (2018), 617-633.

J. Páez Chávez, J. Schreiter, S. Siegmund, C. Mayr.
A continuation approach for computing parameter-dependent separatrices in SRAM cells.
Applied Mathematical Modelling 64 (2018), 106-120.

T.S. Doan, J. Páez Chávez, S. Siegmund.
A characterization of the distance between controllable and uncontrollable LTI systems.
2018 23rd International Conference on Methods & Models in Automation & Robotics (MMAR), IEEE Xplore (2018), doi:10.1109/MMAR.2018.8486092

K. Kitzing, R. Picard, S. Siegmund, S. Trostorff, M. Waurick.
A Hilbert space approach to difference equations.
Springer Proceedings in Mathematics & Statistics, entitled: Recent Progress in Difference Equations, Discrete Dynamical Systems and Applications, Editors S. Elaydi, C. Pötzsche, A.L. Sasu (2018), to appear.

S. Siegmund.
Protecting against hurricane damage with mathematics.
Notices of the American Mathematical Society 65:8 (2018), 967-968.

J. Páez Chávez, D. Jungmann, S. Siegmund.
A comparative study of integrated pest management strategies based on impulsive control.
Journal of biological dynamics 12:1 (2018), 318-341.

L.H. Duc, S. Siegmund.
A concept of local metric entropy for finite-time nonautonomous dynamical systems.
Journal of Difference Equations and Applications 24 (2018), 165-179, doi:10.1080/10236198.2016.1267154

J. Páez Chávez, D. Jungmann, S. Siegmund.
Modeling and analysis of integrated pest control strategies via impulsive differential equations.
International Journal of Differential Equations, Volume 2017 (2017), Article ID 1820607, 18 pages, doi:10.1155/2017/1820607

J. Ren, L. Yu, S. Siegmund.
Bifurcations and chaos in a discrete predator–prey model with Crowley–Martin functional response.
Nonlinear Dynamics 90 (2017), 19-41, doi:10.1007/s11071-017-3643-6

K. Diethelm, S. Siegmund, H.T. Tuan.
Asymptotic behavior of solutions of linear multi-order fractional differential systems.
Fractional Calculus & Applied Analysis 20 (2017), 1165-1195.

B. Garay, S. Siegmund, S. Trostorff, M. Waurick.
Some remarks on local activity and local passivity.
International Journal of Bifurcation and Chaos 27 (2017), 1750057.

N.D. Cong, D.T. Son, S. Siegmund, H.T. Tuan.
An instability theorem for nonlinear fractional differential systems.
Discrete and Continuous Dynamical Systems. Series B 22 (2017), 3079-3090.

M. Behrisch, S. Kerkhoff, R. Pöschel, F.M. Schneider, S. Siegmund.
Dynamical systems in categories.
Applied Categorical Structures 25 (2017), 29-57.

J. Páez Chávez, T. Götz, S. Siegmund, K.P. Wijaya.
An SIR-Dengue transmission model with seasonal effects and impulsive control.
Mathematical Biosciences (2017), doi.org/10.1016/j.mbs.2017.04.005

M.J. Körber, S. Siegmund.
Elastic model for a wind-protection membrane.
Journal of Wind Engineering and Industrial Aerodynamics 165 (2017), 131-136.

M. Salimi, T. Lotfi, S. Sharifi, S. Siegmund.
Optimal Newton-Secant like methods without memory for solving nonlinear equations with its dynamics.
International Journal of Computer Mathematics (2016), 1-19.

A.L. Do, S. Boccaletti, J. Epperlein, S. Siegmund, T. Gross.
Topological stability criteria for networking dynamical systems with Hermitian Jacobian.
European Journal of Applied Mathematics 27 (2016), 888-903.

J. Páez Chávez, A. Voigt, J. Schreiter, U. Marschner, S. Siegmund, A. Richter.
A new self-excited chemo-fluidic oscillator based on stimuli-responsive hydrogels: Mathematical modeling and dynamic behavior.
Applied Mathematical Modelling 40 (2016), 9719-9738.

N.D. Cong, T.S. Doan, S. Siegmund, H.T. Tuan.
On stable manifolds for fractional differential equations in high-dimensional spaces.
Nonlinear Dynamics 86 (2016), 1885-1894. doi:10.1007/s11071-016-3002-z

M. Budišić, S. Siegmund, T.S. Doan, I. Mezic.
Mesochronic classification of trajectories in incompressible 3D vector fields over finite times.
Discret. Contin. Dyn. S. Ser. S 9 (2016), 923-958.

S. Sharifi, M. Ferrara, M. Salimi, S. Siegmund.
New modification of Maheshwari’s method with optimal eighth order convergence for solving nonlinear equations.
Open Mathematics 14 (2016), 443-451.

B.X. Dieu, L.H. Duc, S. Siegmund, N.V. Minh.
Asymptotic behavior of linear almost periodic differential equations.
In: Mathematical Sciences with Multidisciplinary Applications, Volume 157 of the series Springer Proceedings in Mathematics & Statistics (2016), 113-132.

L.H. Duc, J. Páez Chávez, D.T. Son, S. Siegmund.
Finite-time Lyapunov exponents and metabolic control coefficients for threshold detection of stimulus–response curves.
Journal of Biological Dynamics 10 (2016), 379-394.

N.D. Cong, D.T. Son, S. Siegmund, H.T. Tuan.
Linearized asymptotic stability for fractional differential equations.
Electron. J. Qual. Theory Differ. Equ. 39 (2016), 1-13.

S. Sharifi, S. Siegmund, M. Salimi.
Solving nonlinear equations by a derivative-free form of the King’s family with memory.
Calcolo 53 (2016), 201-215.

J. Diblik, C. Nowak, S. Siegmund.
A generalized Picard–Lindelöf theorem.
Electron. J. Qual. Theory Differ. Equ. 28 (2016), 1-8.

S. Sharifi, M. Salimi, S. Siegmund, T. Lotfi.
A new class of optimal four-point methods with convergence order 16 for solving nonlinear equations.
Math. Comput. Simulat. 119 (2016), 69-90.

J. Ren, L. Zhang, S. Siegmund.
How inhomogeneous site percolation works on Bethe lattices: Theory and applications.
Scientific Reports (2016), 1-11.

M. Salimi, G.I. Ibragimov, S. Siegmund, S. Sharifi.
On a fixed duration pursuit differential game with geometric and integral constraints.
Dynamic Games and Applications 6 (2016), 409–425.

G. Paschew, J. Schreiter, A. Voigt, C. Pini, J. Páez Chávez, M. Allerdißen, U. Marschner, S. Siegmund, R. Schüffny, F. Jülicher, A. Richter.
Autonomous chemical osciallator circuit based on bidirectional chemical-microfluidic coupling.
Adv. Mater. Technol. (2016), 1-6.

J. Epperlein, S. Siegmund, P. Stehlik, V. Svigler.
Coexistence equilibria of evolutionary games on graphs under deterministic imitation dynamics.
Discret. Contin. Dyn. S. Ser. B 3 (2016), 803-813.

S. Sharifi, S. Siegmund, M. Salimi.
Solving nonlinear equations by a derivative-free form of the King's family with memory.
Calcolo 53 (2016), 201–215.

L.H. Duc, D. Christmann, R. Gotzhein, S. Siegmund, F. Wirth
The stability of Try-Once-Discard for stochastic communication channels: Theory and validation.
2015 IEEE 54th Annual Conference on Decision and Control (CDC), 15-18 Dec. 2015, pp. 4170-4175.

F. Wang, J. Chu, S. Siegmund.
Periodic solutions for second order singular differential systems with parameters.
Topol. Methods Nonlinear Anal. 46 (2015), 549-562.

J. Chu, F.-F. Liao, S. Siegmund, Y. Xia, W. Zhang.
Nonuniform dichotomy spectrum and reducibility for nonautonomous equations.
Bull. Sci. Math. 139 (2015), 538-557.

B.X. Dieu, S. Siegmund, N.V. Minh.
A Katznelson–Tzafriri type theorem for almost periodic linear evolution equations.
Vietnam Journal of Mathematics 43 (2015), 403–415.

H.D. Luu, B. Schmalfuß, S. Siegmund.
A note on the generation of random dynamical systems from fractional stochastic delay differential equations.
Stoch. Dyn. 15 no. 3 (2015), 1550018-1-13.

J. Epperlein, S. Siegmund, P. Stehlik.
Evolutionary games on graphs and discrete dynamical systems.
J. Differ. Equ. Appl. 21 no. 2 (2015), 72-95.

N.D. Cong, D.T. Son, S. Siegmund.
On Lyapunov exponents of difference equations with random delay.
Discret. Contin. Dyn. S. Ser. B 20 (2015), 861-874.

P. Bonckaert, P. De Maesschalck, T.S. Doan, S. Siegmund.
Partial linearization for planar nonautonomous differential equations.
J. Differential Equations 258 (2015), 1618-1652.

T.S. Doan, A. Kalauch, M. Klose, S. Siegmund.
Stability of positive linear switched systems on ordered Banach spaces.
Systems & Control Letters 75 (2015), 14-19.

T. Lotfi, S. Sharifi, M. Salimi, S. Siegmund.
A new class of three-point methods with optimal convergence order eight and its dynamics.
Numer. Algor. 68 (2015), 261-288.

J. Diblik, C. Nowak, S. Siegmund.
A general Lipschitz uniqueness criterion for scalar ordinary differential equations.
Electron. J. Qual. Theory Differ. Equ. 34 (2014), 1-6.

J. Ren, C. Chen, G. Wang, W.-S. Cheung, B. Sun, N. Mattern, S. Siegmund, J. Eckert.
Various sizes of sliding event bursts in the plastic flow of metallic glasses based on a spatiotemporal dynamic model.
J. Appl. Phys. 116, 033520 (2014); doi: 10.1063/1.4890720.

A. Kalauch, R. Picard, S. Siegmund, S. Trostorff, M. Waurick.
A Hilbert space perspective on ordinary differential equations with memory term.
J. Dyn. Diff. Equat. 26 (2014), 369-399.

N.D. Cong, S. Siegmund, N.T. The.
Adjoint equation and Lyapunov regularity for linear stochastic differential algebraic equations of index 1.
Stochastics, doi: 10.1080/17442508.2013.879141.

Q. Cao, J. Pastor, S. Piskarev, S. Siegmund.
The approximations of parabolic equations at the vicinity of hyperbolic equilibrium point.
Numer. Func. Anal. Opt. 35 (2014), 1287-1307.

N.D. Cong, T.S. Doan, S. Siegmund, H.T. Tuan.
On stable manifolds for planar fractional differential equations.
Appl. Math. Comput. 226 (2014), 157-168.

D. Christmann, R. Gotzhein, S. Siegmund, F. Wirth.
Realization of try-once-discard in wireless multi-hop networks.
IEEE Trans. Ind. Informat. 10 (2014), 17-26.

N.D. Cong, T.S. Doan, H.T. Tuan, S. Siegmund.
Structure of the fractional Lyapunov spectrum for linear fractional differential equations.
Adv. Dyn. Syst. Appl. 9 (2014), 149-159.

2009-2013

T.S. Doan, A. Kalauch, S. Siegmund.
Hyperbolicity radius of time-invariant linear systems.
Proceedings of the International Conference on Differential & Difference Equations and Applications 47 (2013), 113-125.

F.M. Schneider, S. Kerkhoff, M. Behrisch, S. Siegmund.
Locally compact groups admitting faithful strongly chaotic actions on Hausdorff spaces.
Int. J. Bifurcat. Chaos 23, 1350158 (2013), doi: 10.1142/S0218127413501587.

F.M. Schneider, S. Kerkhoff, M. Behrisch, S. Siegmund.
Chaotic actions of topological semigroups.
Semigroup Forum 87 (2013), 590-598.

C. Kühn, S. Siegmund, T. Gross.
Dynamical analysis of evolution equations in generalized models.
IMA J. Appl. Math. 78 (2013), 1051-1077.

J. Epperlein, S. Siegmund.
Phase-locked trajectories for dynamical systems on graphs.
Discret. Contin. Dyn. S. Ser. B 18 (2013), 1827-1844.

J. Epperlein, A.L. Do, T. Gross, S. Siegmund.
Meso-scale obstructions to stability of 1D center manifolds for networks of coupled differential equations with symmetric Jacobian.
Physica D 261 (2013), 1-7.

T.S. Doan, S. Siegmund.
Differential equations with random delay.
Fields Inst. Commun. 64 (2013), 279-303.

T.S. Doan, A. Kalauch, S. Siegmund.
A constructive approach to linear Lyapunov functions for positive switched systems using Collatz-Wielandt sets.
IEEE Trans. Automat. Control 58 (2013), 748-751.

T.S. Doan, S. Siegmund.
Finite-time attractivity for diagonally dominant systems with off-diagonal delays.
Abstract and Applied Analysis (2012), Article ID210156, 10 pages, doi:10.1155/2012/210156.

T.S. Doan, D. Karrasch, T.Y. Nguyen, S. Siegmund.
A unified approach to finite-time hyperbolicity which extends finite-time Lyapunov exponents.
J. Differential Equations 252 (2012), 5535-5554.

T.S. Doan, M. Moussi, S. Siegmund.
Integral manifolds of nonautonomous boundary Cauchy problems.
J. Nonl. Evol. Equ. Appl. 1 (2012), 1-15.

T. Gross, S. Siegmund.
Generalized models for high-throughput analysis of uncertain nonlinear systems.
J. Math. Ind. (2011), 1:9, doi:10.1186/2190-5983-1-9.

J. Ren, Z. Cheng, S. Siegmund.
Neutral operator and neutral differential equation.
Abstract and Applied Analysis (2011), Article ID 969276, 29 pages, doi:10.1155/2011/969276.

Y. Chen, J. Ren, S. Siegmund.
Green's function for third-order differential equations.
Rocky Mt. J. Math. 41 (2011), 1417-1478.

L.H. Duc, S. Siegmund.
Existence of finite-time hyperbolic trajectories for planar Hamiltonian flows.
J. Dyn. Diff. Equat. 23 (2011), 475-494.

T.Y. Nguyen, T.S. Doan, T. Jäger, S. Siegmund.
Nonautonomous saddle-node bifurcations in the quasiperiodically forced logistic map.
Intern. J. Bifur. Chaos Appl. Sci. Engrg. 5 (2011), 1427-1438.

J. Ren, S. Siegmund, Y. Chen.
Positive periodic solutions for third-order nonlinear differential equations.
Electron. J. Differ. Equ. 2011 No. 66 (2011), 1-19.

J. Ren, Z. Cheng, S. Siegmund.
Positive periodic solution for Brillouin electron beam focusing system.
Discret. Contin. Dyn. S. 16 (2011), 385-392.

T.S. Doan, K. Palmer, S. Siegmund.
Transient spectral theory, stable and unstable cones and Gershgorin’s theorem for finite-time differential equations.
J. Differential Equations 250 (2011), 4177-4199.

M. Zumsande, D. Stiefs, S. Siegmund, T. Gross.
General analysis of mathematical models for bone remodeling.
Bone 48 (2011), 910-917.

N. Koksch, S. Siegmund.
Feedback control via inertial manifolds for nonautonomous evolution equations.
Communications on Pure and Applied Analysis 10 (2011), 917-936.

T.S. Doan, A. Kalauch, S. Siegmund, F. Wirth.
Stability radii for positive linear time-invariant systems on time scales.
Systems & Control Letters 59 (2010), 173-179.

A. Jentzen, F. Leber, D. Schneisgen, A. Berger, S. Siegmund.
An improved maximum allowable transfer interval for Lp-stability of networked control systems.
IEEE Trans. Automat. Control 55 (2010), 179-184.

Z. Cheng, J. Ren, S. Siegmund.
Periodic solution for generalized high-order delay differential equations.
Asian-European Journal of Mathematics 3 (2010), 29-41.

H. Crauel, T.S. Doan, S. Siegmund.
Difference equations with random delay.
Journal of Difference Equations and Applications 15 (2009), 627-647.

A. Berger, T.S. Doan, S. Siegmund.
A definition of spectrum for differential equations on finite time.
J. Differential Equations 246 (2009), 1098-1118.

N.V. Minh, G. Nguerekata, S. Siegmund.
Circular spectrum and bounded solutions of periodic evolution equations.
J. Differential Equations 246 (2009), 3089-3108.

T.S. Doan, A. Kalauch, S. Siegmund.
Exponential stability of linear time-invariant systems on time scales.
Nonlinear Dyn. Syst. Theory 9 (2009), 37-50.

2004-2008

A. Berger, S. Siegmund.
Uniformly attracting solutions of nonautonomous differential equations.
Nonlinear Analysis 68 (2008), 3789-3811.

A. Berger, T.S. Doan, S. Siegmund.
A Remark on Finite-Time Hyperbolicity.
PAMM, Proc. Appl. Math. Mech. 8 (2008), 10917-10918.

N.D. Cong, L.H. Duc, S. Siegmund.
A computational ergodic theorem for infinite iterated function systems.
Stoch. Dyn. 8 (2008), 365-381.

A. Berger, T.S. Doan, S. Siegmund.
Nonautonomous finite-time dynamics.
Discret. Contin. Dyn. S. 9 (2008), 463-492.

L.H. Duc, S. Siegmund.
Hyperbolicity and invariant manifolds for planar nonautonomous systems on finite time intervals.
Intern. J. Bifur. Chaos Appl. Sci. Engrg. 3 (2008), 641-674.

P. Kloeden, L. Grüne, S. Siegmund, F. Wirth.
Lyapunov's second method for nonautonomous differential equations.
Discret. Contin. Dyn. S. 18 (2007), 375-403.

J. Duan, C. Pötzsche, S. Siegmund.
Slow integral manifolds for Lagrangian fluid dynamics in unsteady geophysical flows.
Physica D 233 (2007), 73-82.

A. Berger, S. Siegmund.
On the distribution of mantissae in nonautonomous difference equations.
J. Differ. Equations Appl. 13 (2007), 829-845.

R.L. Devaney, M.M. Rocha, S. Siegmund.
Rational maps with generalized Sierpinski gasket Julia sets.
Topology Appl. 154 (2007), 11-27.

L.H. Duc, A. Ilchmann, S. Siegmund, P. Taraba.
On stability of linear time-varying second-order differential equations.
Quart. Appl. Math. 64 (2006), 137-151.

F. Colonius, S. Hilger, P. Kloeden, S. Siegmund (eds.).
Special issue dedicated to the memory of Bernd Aulbach.
J. Differ. Equations Appl., Vol. 12, Numbers 3 and 4 (2006).

B. Aulbach, M. Rasmussen, S. Siegmund.
Invariant manifolds as pullback attractors of nonautonomous differential equations.
Discret. Contin. Dyn. S. Ser. A 15 (2006), 579-596.

S. Siegmund, P. Taraba.
Approximation of box dimension of attractors using the subdivision algorithm.
Dyn. Syst. 21 (2006), 1-24.

P. Blanchard, R.L. Devaney, D.M. Look, M.M Rocha, P. Seal, S. Siegmund, D. Uminsky.
Sierpinski carpets and gaskets as Julia sets of rational maps.
Dynamics on the Riemann Sphere, ed., P. Horth and C. Petersen.
European Math Society, 2006, 97-119.

B. Aulbach, M. Rasmussen, S. Siegmund.
Invariant manifolds as pullback attractors of nonautonomous difference equations.
Proc. of 8th ICDEA. eds: B. Aulbach, S. Elaydi, G. Ladas, O. Dosly, CRC, Boca Raton (2005), 215-227.

B. Aulbach, M. Rasmussen, S. Siegmund.
Approximation of attractors of nonautonomous dynamical systems.
Discret. Contin. Dyn. S. Ser. B 5 (2005), 215-238.

I. Chueshov, S. Siegmund.
On dimension and metric properties of trajectory attractors.
J. Dynam. Differential Equations 17 (2005), 621-641.

P.E. Kloeden, S. Siegmund.
Bifurcations and continuous transitions of attractors in autonomous and nonautonomous systems.
Internat. J. Bifur. Chaos Appl. Sci. Engrg. 15 (2005), 1-21.

S. Siegmund.
Computation of nonautonomous invariant manifolds.
Proc. of 6th ICDEA, eds: B. Aulbach, S. Elaydi, G. Ladas, Taylor & Francis, London, (2004), 215-227.

C. Pötzsche, S. Siegmund.
C^m-smoothness of invariant fiber bundles for dynamic equations on measure chains.
Advances in Difference Equations 2 (2004), 141-182.

H. Crauel, L.H. Duc, S. Siegmund.
Towards a Morse theory for random dynamical systems.
Stoch. Dyn. 4 (2004), 277-296.

I. Chueshov, M. Polat, S. Siegmund.
Gevrey regularity of global attractor for generalized Benjamin-Bona-Mahony equation.
Mat. Fiz. Anal. Geom. 11 (2004), 226-242.

A. Berger, S. Siegmund, Y. Yi.
On almost automorphic dynamics in symbolic lattices.
Ergodic Theory Dynam. Systems 24 (2004), 677-696.

J. López Fenner, S. Siegmund.
An (h,k) dichotomy spectrum for systems of linear differential equations with impulse effect.
Dynam. Contin. Discrete Impuls. Systems 11 (2004), 1-17.

C. Pötzsche, S. Siegmund.
A limit set trichotomy for order-preserving systems on time scales.
Electron. J. Differential Equations 64 (2004), 1-18.

K. Palmer, S. Siegmund.
Generalized attractor-repeller pairs, diagonalizability and integral separation.
Adv. Nonlinear Stud. 4 (2004), 189-207.

1999-2003

A. Berger, S. Siegmund.
On the gap between random dynamical systems and continuous skew products.
J. Dynam. Differential Equations 15 (2003), 237-279.

H. Leiva, S. Siegmund.
A necessary algebraic condition for controllability and observability of linear time-varying systems.
IEEE Trans. Automat. Control 48 No. 12 (2003), 2229-2232.

F. Colonius, S. Siegmund.
Normal forms for control systems at singular points.
J. Dynam. Differential Equations 15 (2003), 49-59.

C. Pötzsche, S. Siegmund, F. Wirth.
A spectral characterization of exponential stability for linear time-invariant systems on time scales.
Discret. Contin. Dyn. S. 9 (2003), 1223-1241.

N. Koksch, S. Siegmund.
Cone invariance and squeezing properties for inertial manifolds of nonautonomous evolution equations.
Banach Center Publications 60 (2003), 27-48.

S. Siegmund.
Normal forms for nonautonomous difference equations.
Advances in Difference Equations IV. Comput. Math. Appl. 45 (2003), 1059-1073.

N. Koksch, S. Siegmund.
Inertial manifolds for nonautonomous evolution equations.
Progress in analysis, Vol. I, II (Berlin, 2001), World Sci. Publishing, River Edge, NJ, 2003, 545-553.

N. Koksch, S. Siegmund.
Pullback attracting inertial manifolds for nonautonomous dynamical systems.
J. Dynam. Differential Equations 14 (2002), 889-941.

N.D. Cong, S. Siegmund.
Dichotomy spectrum of nonautonomous linear stochastic differential equations.
Stoch. Dyn. 2 (2002), 175-201.

B. Aulbach, C. Pötzsche, S. Siegmund.
A smoothness theorem for invariant fiber bundles.
J. Dynam. Differential Equations 14 (2002), 519-547.

S. Siegmund.
Reducibility of nonautonomous linear differential equations.
J. London Math. Soc. 65 (2002), 397-410.

S. Siegmund.
Dichotomy spectrum for nonautonomous differential equations.
J. Dynam. Differential Equations 14 (2002), 243-258.

S Siegmund.
Normal forms for nonautonomous differential equations.
J. Differential Equations 178, 541-573.

S. Siegmund.
A spectral notion for dynamic equations on time scales.
J. Comput. Appl. Math. 141 (2002), 255-265.

S. Siegmund.
Block diagonalization of linear difference equations.
J. Differ. Equations Appl. 8 (2002), 177-189.

N. Koksch, S. Siegmund.
Inertial manifolds for nonautonomous dynamical systems and for nonautonomous evolution equations.
Proc. of Equadiff 2001, Masaryk University Press, Brno, 221-266.

B. Aulbach, S. Siegmund.
The dichotomy spectrum for noninvertible systems of linear difference equations.
J. Differ. Equations Appl. 7 (2001), 895-913.

S. Siegmund.
Normal form of Duffing-van der Pol oscillator under nonautonomous parametric perturbations.
Proc. of Int. Conference on Dynamical Systems and Differential Equations, Atlanta/USA, published as added volume of Discrete Contin. Dyn. Syst. (2000), 357-361.

B. Aulbach, S. Siegmund.
A spectral theory for nonautonomous difference equations.
Proc. of 5th Int. Conference on Difference Equations and Applications, Temuco/Chile, 45-55, 2000.

S. Siegmund.
Local theory for differential equations of Carathéodory type.
Proc. of Equadiff 1999, Berlin, 871-873, World Sci. Publishing, River Edge, NJ, 2000.

S. Siegmund.
Spektraltheorie, glatte Faserungen und Normalformen für Differentialgleichungen vom Carathéodory-Typ.
Dissertation. University of Augsburg. 1999.