13,985 research outputs found
Integration of Lie Algebroid Comorphisms
We show that the path construction integration of Lie algebroids by Lie
groupoids is an actual equivalence from the category of integrable Lie
algebroids and complete Lie algebroid comorphisms to the category of source
1-connected Lie groupoids and Lie groupoid comorphisms. This allows us to
construct an actual symplectization functor in Poisson geometry. We include
examples to show that the integrability of comorphisms and Poisson maps may not
hold in the absence of a completeness assumption.Comment: 28 pages, references adde
Symplectic Microgeometry III: Monoids
We show that the category of Poisson manifolds and Poisson maps, the category
of symplectic microgroupoids and lagrangian submicrogroupoids (as morphisms),
and the category of monoids and monoid morphisms in the microsymplectic
category are equivalent symmetric monoidal categories.Comment: 19 pages, 2 figure
Chromatographic test facility. Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration
Test facility to verify design concepts and mathematical models of chromatograph for atmospheric composition analysis of Mar
On the persistence of two small-scale problems in {\Lambda}CDM
We investigate the degree to which the inclusion of baryonic physics can
overcome two long-standing problems of the standard cosmological model on
galaxy scales: (i) the problem of satellite planes around Local Group galaxies,
and (ii) the "too big to fail" problem. By comparing dissipational and
dissipationless simulations, we find no indication that the addition of
baryonic physics results in more flattened satellite distributions around
Milky-Way-like systems. Recent claims to the contrary are shown to derive in
part from a non-standard metric for the degree of flattening, which ignores the
satellites' radial positions. If the full 3D positions of the satellite
galaxies are considered, none of the simulations we analyse reproduce the
observed flattening nor the observed degree of kinematic coherence of the Milky
Way satellite system. Our results are consistent with the expectation that
baryonic physics should have little or no influence on the structure of
satellite systems on scales of hundreds of kiloparsecs. Claims that the "too
big to fail" problem can be resolved by the addition of baryonic physics are
also shown to be problematic.Comment: 13 pages, 5 figures. Accepted for publication in ApJ. Partially
written in response to arXiv:1412.274
- …