1,196 research outputs found
Generic elements in isometry groups of Polish ultrametric spaces
This paper presents a study of generic elements in full isometry groups of
Polish ultrametric spaces. We obtain a complete characterization of Polish
ultrametric spaces X whose isometry group Iso(X) contains an open subgroup H
with ample generics. It also gives a characterization of the existence of an
open subgroup in Iso(X) with a comeager conjugacy class.
We also study the transfinite sequence defined by the projection of a Polish
ultrametric space X on the ultrametric space of orbits of X under the action of
Iso(X)
On derived equivalence classification of gentle two-cycle algebras
We classify, up to derived (equivalently, tilting-cotilting) equivalence all
nondegenerate gentle two-cycle algebras. We also give a partial classification
and formulate a conjecture in the degenerate case
Obituary: Jarema Malicki (1965-2019).
Jarema Malicki, a pioneer in developmental studies of the vertebrate retina, died on 4th January 2019, shortly after being diagnosed with cancer. Here, I reflect on Jarema's life and work, with a particular focus on his research interests in zebrafish as a model organism for vertebrate retinogenesis and human ciliopathies
Cooperative Boolean systems with generically long attractors II
We prove that cooperativity in Boolean networks precludes a strong notion of
sensitive dependence on initial conditions. Weaker notions of sensitive
dependence are shown to be consistent with cooperativity, but if each
regulatory functions is binary AND or binary OR, in N-dimensional networks they
impose an upper bound of approximately sqrt(3)^N on the lengths of attractors
that can be reached from a fraction p approaching 1 of initial conditions. The
upper bound is shown to be sharp
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