http://www.tu-ilmenau.de

Logo TU Ilmenau



Foto des Ansprechpartners
Ansprechpartner

Prof. Dr. Achim Ilchmann

Head of Group

Telefon +49 3677 69-3623

E-Mail senden


Ihre Position

INHALTE

Veröffentlichungen

Anzahl der Treffer: 424
Erstellt: Mon, 18 Jan 2021 23:12:46 +0100 in 0.0353 sec


Strauss, Vladimir Abramovich; Trunk, Carsten
Some Sobelev spaces as Pontryagin spaces. - In: Vestnik Južno-Ural'skogo Gosudarstvennogo Universiteta. Serija matematika, mechanika, fizika / Južno-Uralьskij gosudarstvennyj universitet. - Čeljabinsk, 2014- , ISSN: 2075-809X , ZDB-ID: 2701282-7, ISSN 2075-809X, Bd. 6.2012, 11 (270), S. 14-23

We show that well known Sobolev spaces can quite naturally be treated as Pontryagin spaces. This point of view gives a possibility to obtain new properties for some traditional objects such as simplest differential operators.



Anderson, Brian D. O.; Ilchmann, Achim; Wirth, Fabian R.
Stabilization of linear time-varying systems. - Ilmenau : Techn. Univ., Inst. für Mathematik, 2012. - Online-Ressource (PDF-Datei: 21 S., 272,6 KB). . - (Preprint. - M12,14)
http://www.db-thueringen.de/servlets/DocumentServlet?id=21511
Möws, Roland;
On similarity of indefinite Sturm-Liouville operators. - In: Proceedings in applied mathematics and mechanics : PAMM.. - Weinheim [u.a.] : Wiley-VCH, ISSN 1617-7061, Bd. 12 (2012), 1, S. 771-772

http://dx.doi.org/10.1002/pamm.201210374
Berger, Thomas;
On perturbations in the leading coefficient matrix of time-varying index-1 DAEs. - In: Proceedings in applied mathematics and mechanics : PAMM.. - Weinheim [u.a.] : Wiley-VCH, ISSN 1617-7061, Bd. 12 (2012), 1, S. 793-796

http://dx.doi.org/10.1002/pamm.201210382
Knobloch, Jürgen; Vielitz, Martin; Wagenknecht, Thomas
Non-reversible perturbations of homoclinic snaking scenarios. - In: Nonlinearity : ... a journal of the Institute of Physics and the London Mathematical Society.. - Bristol : IOP Publ., ISSN 1361-6544, Bd. 25 (2012), 12, S. 3469-3485

http://dx.doi.org/10.1088/0951-7715/25/12/3469
Winkler, Henrik; Woracek, Harald
Reparametrizations of non trace-normed Hamiltonians. - In: Spectral theory, mathematical system theory, evolution equations, differential and difference equations. - Basel : Birkhäuser, (2012), S. 667-690

Behrndt, Jussi; Möws, Roland; Trunk, Carsten
On finite rank perturbations of selfadjoint operators in Krein spaces and eigenvalues in spectral gaps. - Ilmenau : Techn. Univ., Inst. für Mathematik, 2012. - Online-Ressource (PDF-Datei: 10 S., 150,6 KB). . - (Preprint. - M12,12)

It is shown that the finiteness of eigenvalues in a spectral gap of a definitizable or locally definitizable selfadjoint operator in a Krein space is preserved under finite rank perturbations. This results is applied to a class of singular Sturm-Liouville operators with an indefinite weight function.



http://www.db-thueringen.de/servlets/DocumentServlet?id=20974
Philipp, Friedrich; Trunk, Carsten;
The numerical range of non-negative operators in Krein spaces. - Ilmenau : Techn. Univ., Inst. für Mathematik, 2012. - Online-Ressource (PDF-Datei: 21 S., 177,7 KB). . - (Preprint. - M12,11)

We define and characterize the Krein space numerical range W(A) and the Krein space co-numerical range W_{\rm co}(A) of a non-negative operator A in a Krein space. It is shown that the non-zero spectrum of A is contained in the closure of W(A)\cap W_{\rm co}(A).



http://www.db-thueringen.de/servlets/DocumentServlet?id=20973
Berger, Thomas; Ilchmann, Achim; Reis, Timo
Normal forms, high-gain, and funnel control for linear differential-algebraic systems. - In: Control and optimization with differential-algebraic constraints. - Philadelphia, Pa. : SIAM, Soc. for Industrial and Applied Mathematics, (2012), S. 127-164

Berger, Thomas;
Robustness of stability of time-varying index-1 DAEs. - Ilmenau : Techn. Univ., Inst. für Mathematik, 2012. - Online-Ressource (PDF-Datei: 44 S., 392,0 KB). . - (Preprint. - M12,10)

We study exponential stability and its robustness for time-varying linear index-1 differential-algebraic equations. The effect of perturbations in the leading coefficient matrix is investigated. An appropriate class of allowable perturbations is introduced. Robustness of exponential stability with respect to a certain class of perturbations is proved in terms of the Bohl exponent and perturbation operator. Finally, a stability radius involving these perturbations is introduced and investigated. In particular, a lower bound for the stability radius is derived. The results are presented by means of illustrative examples.



http://www.db-thueringen.de/servlets/DocumentServlet?id=20895