@article{Huber,
  author    = {Huber, Albert},
  title     = {The gravitational field of a massless particle on the horizon of a stationary black hole},
  series = {Classical and Quantum Gravity},
  journal   = {Classical and Quantum Gravity},
  abstract  = {In this work, the field of a gravitational shockwave generated by a massless point-like particle is calculated at the event horizon of a stationary Kerr-Newman black hole. Using the geometric framework of generalized Kerr-Schild deformations in combination with the spin-coefficient formalism of Newman and Penrose, it is shown that the field equations of the theory, at the event horizon of the black hole, can be reduced to a single linear ordinary differential equation for the so-called profile function of the geometry. This differential relation is solved exactly. Based on the results obtained, a physical interpretation is given for the found shockwave spacetime, and it is clarified how these results lead back to those of previous works on the subject, which deal with the much simpler cases of gravitational shockwaves in static black hole backgrounds.},
  subject      = {Gravitation},
  language  = {en}
}
@article{HoffmannKuba,
  author    = {Hoffmann, Michael E. and Kuba, Markus},
  title     = {Logarithmic integrals, zeta values, and tiered binomial coeffcients},
  series = {Monatshefte fuer Mathematik},
  journal   = {Monatshefte fuer Mathematik},
  subject      = {Integrals},
  language  = {en}
}
@article{BelkacemKupkaPhilidetetal.,
  author    = {Belkacem, K{\´e}vin and Kupka, Friedrich and Philidet, Jordan and Samadi, R{\´e}za},
  title     = {Surface effects and turbulent pressure. Assessing the Gas-Γ1 and Reduced-Γ1 empirical models.},
  series = {Astronomy \& Astrophysics},
  journal   = {Astronomy \& Astrophysics},
  subject      = {Surface},
  language  = {en}
}
@article{KubaVarvak,
  author    = {Kuba, Markus and Varvak, Anna},
  title     = {On Path diagrams and Stirling permutations},
  series = {S{\´e}minaire Lotharingien de Combinatoire},
  journal   = {S{\´e}minaire Lotharingien de Combinatoire},
  number    = {B82c (2021)},
  pages     = {28},
  abstract  = {A permutation can be locally classified according to the four local types: peaks, valleys, double rises and double falls. The corresponding classification of binary increasing trees uses four different types of nodes. Flajolet demonstrated the continued fraction representation of the generating function of local types, using a classical bijection between permutations, binary increasing trees, and suitably defined path diagrams induced by Motzkin paths. The aim of this article is to extend the notion of local types from permutations to k-Stirling permutations (also known as k-multipermutations). We establish a bijection of these local types to node types of (k+1)-ary increasing trees. We present a branched continued fraction representation of the generating function of these local types through a bijection with path diagrams induced by Łukasiewicz paths, generalizing the results from permutations to arbitrary k-Stirling permutations. We further show that the generating function of ordinary Stirling permutation has at least three branched continued fraction representations, using correspondences between non-standard increasing trees, k-Stirling permutations and path diagrams.},
  subject      = {Kettenbruch},
  language  = {en}
}
@misc{Kupka,
  author    = {Kupka, Friedrich},
  title     = {Improvements to the Short-Characteristics Method in 3D RHD Simulations and some Unsolved Problems in Spectral Line Shapes of A-type Stars},
  subject      = {Convection},
  language  = {en}
}
@misc{Kupka,
  author    = {Kupka, Friedrich},
  title     = {Improvements in Numerical and Analytical Modelling Techniques to Study the Solar Surface},
  subject      = {Convection},
  language  = {en}
}
@misc{Kupka,
  author    = {Kupka, Friedrich},
  title     = {Advanced Convection Modelling in Asteroseismology and Stellar Evolution},
  subject      = {Convection},
  language  = {en}
}
@article{Huber,
  author    = {Huber, Albert},
  title     = {Hidden Killing fields, geometric symmetries and black hole mergers},
  series = {Annals of Physics},
  volume    = {434},
  journal   = {Annals of Physics},
  pages     = {17},
  abstract  = {In the present work, using the recently introduced framework of local geometric deformations, special types of vector fields - so-called hidden Killing vector fields - are constructed, which solve the Killing equation not globally, but only locally, i.e. in local subregions of spacetime. Taking advantage of the fact that the vector fields coincide locally with Killing fields and therefore allow the consideration of integral laws that convert into exact physical conservation laws on local scales, balance laws in dynamical systems without global Killing symmetries are derived that mimic as closely as possible the conservation laws for energy and angular momentum of highly symmetric models. The utility of said balance laws is demonstrated by a concrete geometric example, namely a toy model for the binary merger of two extremal Reissner-Nordstr{\"o}m black holes.},
  subject      = {Hidden Killing},
  language  = {en}
}
@article{KostogryzKupkaPiskunovetal.,
  author    = {Kostogryz, Nadiia M. and Kupka, Friedrich and Piskunov, Nikolai and Fabbian, Damian and Kr{\"u}ger, Daniel and Gizon, Laurent},
  title     = {Accurate Short-Characteristics Radiative Transfer in A Numerical Tool for Astrophysical Research (ANTARES)},
  series = {Solar Physics},
  journal   = {Solar Physics},
  subject      = {Astrophysics},
  language  = {en}
}
@inproceedings{LietzeLangerKrizek,
  author    = {Lietze, Stefanie and Langer, Karin and Krizek, Gerd Christian},
  title     = {Getting started - eigene Lehrvideos gestalten},
  series = {Conference: Hochschulen im digitalen (Klima)Wandel},
  booktitle = {Conference: Hochschulen im digitalen (Klima)Wandel},
  subject      = {Lehrvideos},
  language  = {de}
}