@misc{BeniniSchenkel2017,
  author    = {Benini, Marco and Schenkel, Alexander},
  title     = {Quantum field theories on categories fibered in groupoids},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {895},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-43154},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-431541},
  pages     = {48},
  year      = {2017},
  abstract  = {We introduce an abstract concept of quantum field theory on categories fibered in groupoids over the category of spacetimes. This provides us with a general and flexible framework to study quantum field theories defined on spacetimes with extra geometric structures such as bundles, connections and spin structures. Using right Kan extensions, we can assign to any such theory an ordinary quantum field theory defined on the category of spacetimes and we shall clarify under which conditions it satisfies the axioms of locally covariant quantum field theory. The same constructions can be performed in a homotopy theoretic framework by using homotopy right Kan extensions, which allows us to obtain first toy-models of homotopical quantum field theories resembling some aspects of gauge theories.},
  language  = {en}
}
@misc{CestnikRosenblum2017,
  author    = {Cestnik, Rok and Rosenblum, Michael},
  title     = {Reconstructing networks of pulse-coupled oscillators from spike trains},
  series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  number    = {760},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-43628},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-436285},
  pages     = {8},
  year      = {2017},
  abstract  = {We present an approach for reconstructing networks of pulse-coupled neuronlike oscillators from passive observation of pulse trains of all nodes. It is assumed that units are described by their phase response curves and that their phases are instantaneously reset by incoming pulses. Using an iterative procedure, we recover the properties of all nodes, namely their phase response curves and natural frequencies, as well as strengths of all directed connections.},
  language  = {en}
}
@misc{PolitiPikovskijUllner2017,
  author    = {Politi, Antonio and Pikovskij, Arkadij and Ullner, Ekkehard},
  title     = {Chaotic macroscopic phases in one-dimensional oscillators},
  series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  number    = {721},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-42979},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-429790},
  pages     = {20},
  year      = {2017},
  abstract  = {The connection between the macroscopic description of collective chaos and the underlying microscopic dynamics is thoroughly analysed in mean-field models of one-dimensional oscillators. We investigate to what extent infinitesimal perturbations of the microscopic configurations can provide information also on the stability of the corresponding macroscopic phase. In ensembles of identical one-dimensional dynamical units, it is possible to represent the microscopic configurations so as to make transparent their connection with the macroscopic world. As a result, we find evidence of an intermediate, mesoscopic, range of distances, over which the instability is neither controlled by the microscopic equations nor by the macroscopic ones. We examine a whole series of indicators, ranging from the usual microscopic Lyapunov exponents, to the collective ones, including finite-amplitude exponents. A system of pulse-coupled oscillators is also briefly reviewed as an example of non-identical phase oscillators where collective chaos spontaneously emerges.},
  language  = {en}
}
@misc{FondellEckertJayetal.2017,
  author    = {Fondell, Mattis and Eckert, Sebastian Oliver and Jay, Raphael Martin and Weniger, Christian and Quevedo, Wilson and Niskanen, Johannes and Kennedy, Brian and Sorgenfrei, Florian and Schick, Daniel and Giangrisostomi, Erika and Ovsyannikov, Ruslan and Adamczyk, Katrin and Huse, Nils and Wernet, Philippe and Mitzner, Rolf and F{\"o}hlisch, Alexander},
  title     = {Time-resolved soft X-ray absorption spectroscopy in transmission mode on liquids at MHz repetition rates},
  series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  number    = {780},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-43752},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-437529},
  pages     = {12},
  year      = {2017},
  abstract  = {We present a setup combining a liquid flatjet sample delivery and a MHz laser system for time-resolved soft X-ray absorption measurements of liquid samples at the high brilliance undulator beamline UE52-SGM at Bessy II yielding unprecedented statistics in this spectral range. We demonstrate that the efficient detection of transient absorption changes in transmission mode enables the identification of photoexcited species in dilute samples. With iron(II)-trisbipyridine in aqueous solution as a benchmark system, we present absorption measurements at various edges in the soft X-ray regime. In combination with the wavelength tunability of the laser system, the set-up opens up opportunities to study the photochemistry of many systems at low concentrations, relevant to materials sciences, chemistry, and biology.},
  language  = {en}
}