124 citations · 648 across the 22 of their papers we have counts for
23 papers
Complexity reduction of large-scale stochastic systems using linear quadratic Gaussian balancing
Tobias Damm, Martin Redmann
In this paper, we consider a model reduction technique for stabilizable and detectable stochastic systems. It is based on a pair of Gramians that we analyze in terms of well-posedn…
Hadamard Powers and Kernel Perceptrons
Tobias Damm, Nicolas Dietrich
We study a relation between Hadamard powers and polynomial kernel perceptrons. The rank of Hadamard powers for the special case of a Boolean matrix and for the generic case of a re…
On Coercivity and the Frequency Domain Condition in Indefinite LQ-Control
Tobias Damm, Birgit Jacob
We introduce a coercivity condition as a time domain analogue of the frequency criterion provided by the famous Kalman-Yakubovich-Popov lemma. For a simple stochastic linear quadra…
Balanced truncation of -positive systems
Christian Grussler, Tobias Damm, Rodolphe Sepulchre
This paper considers balanced truncation of discrete-time Hankel -positive systems, characterized by Hankel matrices whose minors up to order are nonnegative. Our main resul…
Simultaneous hollowisation, joint numerical range, and stabilization by noise
Tobias Damm, Heike Fassbender
We consider orthogonal transformations of arbitrary square matrices to a form where all diagonal entries are equal. In our main results we treat the simultaneous transformation of…
Optimal control of district heating networks using a reduced order model
Markus Rein, Jan Mohring, Tobias Damm +1
We study the optimal control of district heating networks using a reduced order model based on a system theoretic description close to the underlying Euler equations. In the presen…
Model order reduction of hyperbolic systems at the example of district heating networks
Markus Rein, Jan Mohring, Tobias Damm +1
In this article a framework for the generation of a computationally fast surrogate model for district heating networks is presented. An appropriate model results in an index-1 hype…
Levitated cavity optomechanics in high vacuum
Uroš Delić, David Grass, Manuel Reisenbauer +4
We report dispersive coupling of an optically trapped silica nanoparticle (nm diameter) to the field of a driven Fabry-Perot cavity in high vacuum (mbar).…
Riemannian optimal identification method for linear systems with symmetric positive-definite matrix
Kazuhiro Sato, Hiroyuki Sato, Tobias Damm
This study develops identification methods for linear continuous-time symmetric systems, such as electrical network systems, multi-agent network systems, and temperature dynamics i…
Variable Potentials for Thermalized Light and Coupled Condensates
David Dung, Christian Kurtscheid, Tobias Damm +4
For over a decade, cold atoms in lattice potentials have been an attractive platform to simulate phenomena known from solid state theory, as the Mott-insulator transition. In contr…
First-order spatial coherence measurements in a thermalized two-dimensional photonic quantum gas
Tobias Damm, David Dung, Frank Vewinger +2
Phase transitions between different states of matter can profoundly modify the order in physical systems, with the emergence of ferromagnetic or topological order constituting impo…
Numerical solution of Lyapunov equations related to Markov jump linear systems
Tobias Damm, Kazuhiro Sato, Axel Vierling
We suggest and compare different methods for the numerical solution of Lyapunov like equations with application to control of Markovian jump linear systems. First, we consider fixe…
Computing the stochastic -norm
Tobias Damm, Peter Benner, Jan Hauth
The stochastic -norm is defined as the -induced norm of the input-output operator of a stochastic linear system. Like the deterministic -norm it is charact…
Bose-Einstein Condensation of Photons versus Lasing and Hanbury Brown-Twiss Measurements with a Condensate of Light
Julian Schmitt, Tobias Damm, David Dung +3
The advent of controlled experimental accessibility of Bose-Einstein condensates, as realized with e.g. cold atomic gases, exciton-polaritons, and more recently photons in a dye-fi…
Calorimetry of a Bose-Einstein condensed photon gas
Tobias Damm, Julian Schmitt, Qi Liang +4
Phase transitions, as the condensation of a gas to a liquid, are often revealed by a discontinuous behavior of thermodynamic quantities. For liquid Helium, for example, a divergenc…
Spontaneous symmetry breaking and phase coherence of a photon Bose-Einstein condensate coupled to a reservoir
Julian Schmitt, Tobias Damm, David Dung +4
We examine the phase evolution of a Bose-Einstein condensate of photons generated in a dye microcavity by temporal interference with a phase reference. The photo-excitable dye mole…
Dual pairs of generalized Lyapunov inequalities and balanced truncation of stochastic linear systems
Peter Benner, Tobias Damm, Yolanda Rocio Rodriguez Cruz
We consider two approaches to balanced truncation of stochastic linear systems, which follow from different generalizations of the reachability Gramian of deterministic systems. Bo…
Thermalization kinetics of light: From laser dynamics to equilibrium condensation of photons
Julian Schmitt, Tobias Damm, David Dung +3
We report a time-resolved study of the thermalization dynamics and the lasing to photon Bose-Einstein condensation crossover by in-\textit{situ} monitoring the photon kinetics in a…
Observation of grand-canonical number statistics in a photon Bose-Einstein condensate
Julian Schmitt, Tobias Damm, David Dung +3
We report measurements of particle number correlations and fluctuations of a photon Bose-Einstein condensate in a dye microcavity using a Hanbury Brown-Twiss experiment. The photon…
Bose-Einstein Condensation of Photons in a Microscopic Optical Resonator: Towards Photonic Lattices and Coupled Cavities
Jan Klaers, Julian Schmitt, Tobias Damm +3
Bose-Einstein condensation has in the last two decades been observed in cold atomic gases and in solid-state physics quasiparticles, exciton-polaritons and magnons, respectively. T…
Thermalization of a two-dimensional photon gas in a polymeric host matrix
Julian Schmitt, Tobias Damm, Frank Vewinger +2
We investigate thermodynamic properties of a two-dimensional photon gas confined by a dye-filled optical microcavity. A thermally equilibrated state of the photon gas is achieved b…
Statistical physics of Bose-Einstein condensed light in a dye microcavity
Jan Klaers, Julian Schmitt, Tobias Damm +2
We theoretically analyze the temperature behavior of paraxial light in thermal equilibrium with a dye-filled optical microcavity. At low temperatures the photon gas undergoes Bose-…
Bose-Einstein condensation of paraxial light
J. Klaers, J. Schmitt, T. Damm +2
Photons, due to the virtually vanishing photon-photon interaction, constitute to very good approximation an ideal Bose gas, but owing to the vanishing chemical potential a (free) p…