n-Cities Seminar (n-Städte-Seminar)

The n-Cities Seminar is organized by mathematicians from the Universities of Chemnitz, Dresden, Freiberg, Halle and Leipzig as well as the Max Plank Institute for Mathematics in the Sciences in Leipzig (currently by Swanhild Bernstein, Ralph Chill, Thomas Kalmes, Felix Otto, Felix Pogorzelski and Nils Waterstraat) and is dedicated but not restricted to the following fields: If you are interested in information concerning these regular meetings, please subscribe to the mailing list.

Nächstes Treffen:

09.01.2026: Halle

Vorherige Treffen:

16.05.2025: Freiberg

Place: TU Bergakademie Freiberg, seminar room UBH-0209, Neues Universitätsbibliotheks- und Hörsaalzentrum, Campus TUBAF, Winklerstr. 3, 09599 Freiberg

13:00 Jan Hausmann (TU Dresden): Lyapunov couples and regularisation of semigroups

13:35 Guillaume Neuttiens (U Jena): Time-periodic PDE's and Newton Polygons

14:10 Bian Wu (MPI MiS Leipzig): On anomalous dissipation and Euler flows

15:30 Max Hanisch (U Halle-Wittenberg): Polychromatic Surface Waves in Maxwell's Equations

16:05 Sebastian Boldt (TU Chemnitz): A lower bound on the normal radius of hypersurfaces

16:40 Elias Zimmermann (U Leipzig): Entropy and equipartition beyond amenable groups

17:30 Dinner at Stadtwirtschaft Freiberg, Burgstr. 18

17.01.2025: Chemnitz

Place: TU Chemnitz, central lecture hall building (Zentrales Hörsaalgebäude), seminar room C10.111 Reichenhainer Str. 90, 09126 Chemnitz

13:00 Stefan Czimek (U Leipzig): Introduction to the Null Gluing Problem in General Relativity

13:45 Lucas Broux (MPI MiS Leipzig): Renormalization

14:30 Stephan Mescher (U Halle-Wittenberg): Lusternik-Schnirelmann theory and topological complexity

15:45 Janko Stennder (TU Dresden): Markov operators and Riesz* homomorphisms on order unit spaces

16:30 Martha Zimmermann (TU Bergakademie Freiberg): Different Approaches to q-deformed Clifford Analysis

17:15 Dalimil Peša (TU Chemnitz): Rearrangement-invariant quasi-Banach function spaces and their amalgams

18:45 Dinner at Turm-Brauhaus

03.05.2024: Leipzig

Place: Max Planck Institute for Mathematics in the Sciences (E1 05 Leibniz lecture hall), Inselstr. 22, 04103 Leipzig

12:45: J. Miehe (TU Chemnitz): Fermionic integration and perturbations of semigroups

13:30: C. Raithel (TU Dresden): Density fluctuations in weakly interacting particle systems via the Dean-Kawasaki equation

14:15: M. Porfido (TU Bergakademie Freiberg): Kernel estimates for a class of fractional Kolmogorov operators

15:30: N. Doll (Martin-Luther-University Halle-Wittenberg): Orientation flow for real skew-adjoint Fredholm operators with odd-dimensional kernel

16:15: J. Hirsch (U Leipzig): On the Lawson-Osserman conjecture on the minimal surfaces system

17:00: P. Morfe (MPI MiS Leipzig): Minimal Lipschitz Extensions and the Finsler Infinity Laplacian

18:30: Dinner at Barthels Hof

12.01.2024: Dresden

Place: Room C 129, Willers-Building, Zellescher Weg 12-14, 01069 Dresden

13:00: M. Waurick (TU Bergakademie Freiberg): A Hilbert space approach to state-dependent delay equations

13:45: D. Pauly (TU Dresden): Traces for Hilbert complexes

14:30: B. Güneysu (TU Chemnitz): Locally integrable subharmonic functions on local Dirichlet spaces

15:15: Coffee break (Room WIL C 218)

15:45: T. Dohnal (U Halle-Wittenberg): Wavepackets and standing waves at a material interface in nonlinear Maxwell equations

16:30: J. Sauer (U Jena): Optimal Sobolev regularity for degenerate equations of porous media type

Following up at approx. 18:00: After session at Restaurant "Sindbad", Hübnerstr. 13, 01069 Dresden

14.07.2023: Halle

Place: Lecture hall 1.04, Building VSP 1, Von-Seckendorf-Platz 1, 06120 Halle

13:00: M. Wilke (Halle): Fluid flows on surfaces

13:45: M. Müller (U Leipzig): The biharmonic Alt-Caffarelli problem

14:30: E. Döhrer (TU Chemnitz): On a complete Riemannian metric on the space of embedded Ws,2-curves

15:45: A. Buchinger (TU Bergakademie Freiberg): On some Impedance Boundary Conditions for a Thermo-Piezo-Electromagnetic System

16:30: R. Chill (TU Dresden): Nonlinear nonlocal elliptic operators

Following up: Barbecue by the student representatives at the Geological Garden, located nearby the venue; NO registration required

16.12.2022: Freiberg

Place: SPQ-0302 (Schlossplatzquartier, Prüferstr. 4) or https://bbb.hrz.tu-freiberg.de/b/and-hos-zgl-fee

13:00: Christian Seifert (TU Hamburg-Harburg): Some Results on Control Systems in Banach spaces

13:35: Sahiba Ahora (TU Dresden): A tour of eventual positivity

14:10: Raj Dahya (U Leipzig): Approximations and dilations of commuting families of C0-semigroups

15:30: Shayan Alikhanloo (TU Chemnitz): Self-adjoint Laplacians and symmetric diffusions on hyperbolic attractors

16:05: Mathias Schäffner (U Halle):Regularity for non-uniformly elliptic equations

16:40: Lukas Koch (MPI Leipzig): Non-occurrence of global Lavrentiev for vectorial functionals with (p,q)- growth

17:30: Dinner "Schwanenschlößchen zu Freiberg" at Meißner Ring 33, 09599 Freiberg

1.7.2022: Chemnitz

13:00: Nils Waterstraat (Uni Halle-Wittenberg) "The G-equivariant spectral flow and bifurcation of functionals with symmetries"

13:40: Marcel Schmidt (Uni Leipzig) "Weak Hardy/Poincaré inequalities and criticality theory"

14:50: Nathanael Skrepek (TU Bergakademie Freiberg) "Semi-uniform stability of Maxwells equations via a boundary feedback"

15:20: Henrik Schumacher (TU Chemnitz) "Repulsive curves and surfaces"

16:40: Tobias Ried (MPI Leipzig) "Cwikel's bound reloaded"

17:20: Mahamadi Warma (George Mason University, USA) "Turnpike properties for fractional control problems"

The talks will take place in Room N113, Central Lecture Hall (Zentrales Hörsaalgebäude), University of Chemnitz, Reichenhainer Str. 90.

17.1.2020: Leipzig (MPI)

14:00-14:30 (+5): Uta Freiberg (Chemnitz): "Dirichlet forms on quantum graphs with vanishing edge lengths"

14:40-15:10 (+5): Sebastian Boldt (Uni Leipzig): "Scattering Theory of the Dirac operator"

15:15-15:35: coffee and cakes

15:35-16:05 (+5): Leonid Chaichenets (Dresden): "On the global wellposedness of the Klein-Gordon equation for initial data in modulation spaces"

16:15-16:45 (+5): Halit Sevki Aslan (Freiberg): "The influence of time-dependent oscillations on semilinear damped wave models"

16:55-17:25 (+5): María Ángeles García-Ferrero (MPI Leipzig): "Runge approximation properties for local and non-local operators"

ca. 6 pm: Dinner at the restaurant Andria

26.4.2019: Freiberg

13:30 - 14:00: A. Szkola (Leipzig) "On the problem of testing composite hypotheses in non-commutative statistical models"

14:05 - 14:35: B. Claus (Dresden) "Nonlinear Dirichlet forms"

15:40 - 16:10: D. Lorenz (Freiberg) "Linear hyperbolic Cauchy problems with low-regular coefficients"

16:15 - 16:45: C. Bombach (Chemnitz) "Unique determination of a rough potential from boundary data"

16:50 - 17:20: W. Chen (Freiberg) "Elastic waves with different damping mechanisms"

2.11.2018: Leipzig

14:00 - 14:45: Lars Perlich (Dresden) "Dirichlet-to-Robin operators via composition semigroups"

14:45 - 15:30: Michael Wutzig (Freiberg) "Reproducing kernels in harmonic and Clifford analysi"'

15:30 Coffee break

16:00 - 16:45: Jan-Frederik Pietschmann (Chemnitz) "Some remarks on a crossdiffusion equations with size exclusion"

16:45 - 17:30: Florentin Münch (Leipzig) "Liouville property and discrete Ricci curvature"

Venue: Paulinum, Augustusplatz 10, im Felix-Klein-Hörsaal (P501).

29.6.2018: Dresden

13:45-14:30: Jan-David Hardtke (Leipzig) "Octahedral and almost square Banach spaces"

14:30-15:15: Martin Himmel (Freiberg) "New classes of means related to the Cauchy functional equations and their properties"

16:00-16:45: Martin Tautenhahn (Chemnitz/Leipzig) "Null controllability and control costs for the heat equation in unbounded domains"

16:45-17:30: Wolfgang Arendt (Ulm) "Evolution on spaces of continuous functions / Evolution auf Räumen von stetigen Funktionen"

19.1.2018: Chemnitz

14:00-14:45: Sebastian Mildner (Dresden) "Symmetry between the energy of a gradient system and its Lyapunov functions"

14:45-15:30: Christian Seifert (Hamburg) "Operators via Boundary Systems"

16:00-16:45: Tanja Eisner (Leipzig) "Wiener's lemma along primes"

16:45-17:30: David Damanik (Houston) "Localization for the one-dimensional Anderson model via positivity and large deviations for the Lyapunov exponent"

18:30: Joint Dinner at the Turm Brauhaus

Venue: Room B202, Reichenhainer Str. 70, Rühlmann-Bau.

23.6.2017: Freiberg

14:00-14:45:Therese Mieth (Leipzig) "Entropy and approximation numbers of Sobolev embeddings"

14:45-15:30: Christian Rose (Chemnitz) "Heat kernel estimates based on Ricci curvature integral bounds"

16:00-16:45: Lena Malinowski (Dresden) "Operators in pre-Riesz-spaces"

16:45-17:30: Maximilian Reich (Freiberg) "Composition in Weighted Modulation Spaces and Applications to Nonlinear PDEs"

4.11.2016: Leipzig

13:30-14:20: Markus Hartlapp (Dresden) "A quantified version of Ingham's original Tauberian theorem"

15:30-16:30: Abdelaziz Rhandi (Salerno) "Functional analytic methods for stochastic differential operators"

16:30-17:30: Marcel Hansmann (Chemnitz) "On the distribution of eigenvalues of compactly perturbed operators"

29.4.2016: Dresden

13:30-14:20: Mario Helm (Freiberg) Numerische Aspekte der Auswertung der Frechet-Ableitung von Matrix-Exponential-Funktionen

14:30-15:20: Jürgen Voigt (Dresden) Bands in Lp-spaces

15:50-16:40: Thomas Kühn (Leipzig) Optimal approximation of multivariate periodic functions

16:50-17:40: Michela Egidi (Chemnitz) Quantitative uncertainty principle on the torus

30.10.2015: Chemnitz

14:00-14:50: Andras Batkai (Wuppertal) "Approximationen von Evolutionsfamilien"

15:00-15:50: Oliver Rheinbach (TU Freiberg) "Parallel Nonlinear Domain Decomposition Methods in Structural Mechanics"

16:30-17:20: Sascha Trostorff (TU Dresden) "Über eine Klasse maximal monotoner Block-Operator-Matrizen in evolutionären Gleichungen."

18:00: Joint dinner

Venue: Room B202, Reichenhainer Str. 70, Rühlmann-Bau.

6.2.2015: Leipzig

13:30-14:20: Swanhild Bernstein (Freiberg) "Wavelets on Lie groups and homogeneous spaces"

14:30-15:20: Anke Kalauch (Dresden) "Ideale und Bänder in prä-Riesz-Räumen"

15:50-16:40: Dirk Werner (Berlin) "Banachräume mit der Daugavet-Eigenschaft"

16:50-17:40: Daniel Potts (Chemnitz) "High dimensional approximation with trigonometric polynomials"

Venue: Rooms P801 and P501, Augustusplatz 10, Paulinum.

14.10.2014: Dresden

13:30-14:15: Fabian Schwarzenberger (Leipzig) " The integrated density of states on coloured graphs"

14:30-15:15: Martin Tautenhahn (Chemnitz) "Quantitative unique continuation and Wegner estimate for random Schrödinger operators"

16:15-17:00 Yuri Tomilov (Warschau, IMPAN) "From prime numbers to damped waves"

9.5.2014: Chemnitz

13:00-13:45: Konrad Schmüdgen (Leipzig) "Schrödingeroperatoren mit unendlich vielen Punktwechselwirkungen"

14:00-14:45: Thomas Kalmes (Chemnitz) "Eine Vermutung von Treves und ihre Verallgemeinerung auf Ultradistributionen"

15:00-16:00 Coffee break

16:00-16:45 Sebastian Krol (Leipzig) "Fourier multipliers on weighted Lp spaces"

Venue: Room B202, Reichenhainer Str. 70, Rühlmann-Bau.

31.1.2014: Leipzig

15:00-15:45: Peter Stollmann (Chemnitz) "The Complex Laplacian and its Heat Semigroup"

16:15-17:00: Marcus Waurick (Dresden) "Über nicht-autonome, degenerierte Gleichungen"

17:05-17:50: Felix Pogorzelski (Jena) "Convergence of discrete geometries and spectral approximation"

Venue: Room HS 17, Augustplatz 10, Hörsaalgebäude