@article{KellerSchwarz2018,
  author    = {Keller, Matthias and Schwarz, Michael},
  title     = {The Kazdan-Warner equation on canonically compactifiable graphs},
  series = {Calculus of variations and partial differential equations},
  volume    = {57},
  journal   = {Calculus of variations and partial differential equations},
  number    = {2},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0944-2669},
  doi       = {10.1007/s00526-018-1329-7},
  pages     = {18},
  year      = {2018},
  abstract  = {We study the Kazdan-Warner equation on canonically compactifiable graphs. These graphs are distinguished as analytic properties of Laplacians on these graphs carry a strong resemblance to Laplacians on open pre-compact manifolds.},
  language  = {en}
}
@article{KellerSchwarz2020,
  author    = {Keller, Matthias and Schwarz, Michael},
  title     = {Courant's nodal domain theorem for positivity preserving forms},
  series = {Journal of spectral theory},
  volume    = {10},
  journal   = {Journal of spectral theory},
  number    = {1},
  publisher = {EMS Publishing House},
  address   = {Z{\"u}rich},
  issn      = {1664-039X},
  doi       = {10.4171/JST/292},
  pages     = {271 -- 309},
  year      = {2020},
  abstract  = {We introduce a notion of nodal domains for positivity preserving forms. This notion generalizes the classical ones for Laplacians on domains and on graphs. We prove the Courant nodal domain theorem in this generalized setting using purely analytical methods.},
  language  = {en}
}
@article{KellerLenzSchmidtetal.2019,
  author    = {Keller, Matthias and Lenz, Daniel and Schmidt, Marcel and Schwarz, Michael},
  title     = {Boundary representation of Dirichlet forms on discrete spaces},
  series = {Journal de Math{\´e}matiques Pures et Appliqu{\´e}es},
  volume    = {126},
  journal   = {Journal de Math{\´e}matiques Pures et Appliqu{\´e}es},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0021-7824},
  doi       = {10.1016/j.matpur.2018.10.005},
  pages     = {109 -- 143},
  year      = {2019},
  abstract  = {We describe the set of all Dirichlet forms associated to a given infinite graph in terms of Dirichlet forms on its Royden boundary. Our approach is purely analytical and uses form methods. (C) 2018 Elsevier Masson SAS.},
  language  = {en}
}
@article{HinzSchwarz2022,
  author    = {Hinz, Michael and Schwarz, Michael},
  title     = {A note on Neumann problems on graphs},
  series = {Positivity},
  volume    = {26},
  journal   = {Positivity},
  number    = {4},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {1385-1292},
  doi       = {10.1007/s11117-022-00930-0},
  pages     = {23},
  year      = {2022},
  abstract  = {We discuss Neumann problems for self-adjoint Laplacians on (possibly infinite) graphs. Under the assumption that the heat semigroup is ultracontractive we discuss the unique solvability for non-empty subgraphs with respect to the vertex boundary and provide analytic and probabilistic representations for Neumann solutions. A second result deals with Neumann problems on canonically compactifiable graphs with respect to the Royden boundary and provides conditions for unique solvability and analytic and probabilistic representations.},
  language  = {en}
}