489 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Netherlands Institute for Radio AstronomyNL23 papers
- Belarusian State UniversityBY14 papers
- Leibniz Institute for Astrophysics PotsdamDE14 papers
- Polish Academy of SciencesPL14 papers
- Thüringer Landessternwarte TautenburgDE14 papers
- University of ManchesterGB14 papers
- University of WarsawPL14 papers
- Leiden UniversityNL13 papers
- Centre National de la Recherche ScientifiqueFR12 papers
- Radboud University NijmegenNL12 papers
- Rutherford Appleton LaboratoryGB12 papers
- Bielefeld UniversityDE11 papers
11 papers · 1 filter
Symplectic forms invariant under free circle actions on 4--manifolds
Boguslaw Hajduk, Rafal Walczak
Let be a smooth compact manifold with a free circle action generated by a vector field Then for any invariant symplectic form on the contracted form is n…
Geometric discretization of the Bianchi system
A. Doliwa, M. Nieszporski, P. M. Santini
We introduce the dual Koenigs lattices, which are the integrable discrete analogues of conjugate nets with equal tangential invariants, and we find the corresponding reduction of t…
Diffeomorphisms and almost complex structures on tori
Boguslaw Hajduk, Aleksy Tralle
We prove that there exist diffeomorphisms of tori, supported in a disc, which are not isotopic to symplectomorphisms with respect to any symplectic structure. This yields a partial…
Cosmological term, mass, and space-time symmetry
Irina Dymnikova
In the spherically symmetric case the requirements of regularity of density and pressures and finiteness of the ADM mass , together with the weak energy condition, define the fa…
Algebro-geometric solution of the discrete KP equation over a finite field out of a hyperelliptic curve
M. Bialecki, A. Doliwa
We transfer the algebro-geometric method of construction of solutions of the discrete KP equation to the finite field case. We emphasize role of the Jacobian of the underlying alge…
Darboux transformations for 5-point and 7-point self-adjoint schemes and an integrable discretization of the 2D Schrodinger operator
M. Nieszporski, P. M. Santini, A. Doliwa
With this paper we begin an investigation of difference schemes that possess Darboux transformations and can be regarded as natural discretizations of elliptic partial differential…
Regular inflationary cosmology and gauge theories of gravitation
A. V. Minkevich
Cosmological equations for homogeneous isotropic models filled by scalar fields and ultrarelativistic matter are investigated in the framework of gauge theories of gravity. Regular…
A theoretical case for negative mass-square for sub-eV particles
D. V. Ahluwalia-Khalilova, Irina Dymnikova
Electroweak gauge bosons have masses of the order of 10^2 GeV, while masses of additional bosons involved in gravito-electroweak unification are expected to be still higher. These…
Spherically symmetric space-time with the regular de Sitter center
Irina Dymnikova
The requirements are formulated which lead to the existence of the class of globally regular solutions to the minimally coupled GR equations which are asymptotically de Sitter at t…
Nonsingular vacuum cosmologies with a variable cosmological term
K. A. Bronnikov, A. Dobosz, I. G. Dymnikova
We present nonsingular cosmological models with a variable cosmological term described by the second-rank symmetric tensor evolving from to with …
Spherically-symmetric gravitational fields in the metric-affine gauge theory of gravitation
A. V. Minkevich, Yu. G. Vasilevski
Geometric structure of spherically-symmetric space-time in metric-affine gauge theory of gravity is studied. Restrictions on curvature tensor and Bianchi identities are obtained. B…