877 research outputs found
The Agency Problem in the Merger of Vistula & Wólczanka Ltd. and W. Kruk Ltd.
The article discusses the behavior of company bodies and possible conflicts of interests occurring among them during company takeover. In this context, the insider management model, popular in Poland, is discussed. Its implications have been presented using the example of the merger between Vistula & Wólczanka Ltd. and W. Kruk Ltd
A finite generating set for the level 2 mapping class group of a nonorientable surface
We obtain a finite set of generators for the level 2 mapping class group of a
closed nonorientable surface of genus . This set consists of isotopy
classes of Lickorish's Y-homeomorphisms also called crosscap slides.Comment: 13 pages, 3 figure
On finite index subgroups of the mapping class group of a nonorientable surface
Let denote the mapping class group of a compact nonorientable
surface of genus and boundary components, and let
be the subgroup of generated by all Dehn twists. It
is known that is the unique subgroup of of index .
We prove that (and also ) contains a unique subgroup
of index up to conjugation, and a unique subgroup of index
up to conjugation, where . The other
proper subgroups of and have index greater than
. In particular, the minimum index of a proper subgroup of
is .Comment: To appear in Glas. Ma
On the commutator length of a Dehn twist
We show that on a nonorientable surface of genus at least 7 any power of a
Dehn twist is equal to a single commutator in the mapping class group and the
same is true, under additional assumptions, for the twist subgroup, and also
for the extended mapping class group of an orientable surface of genus at least
3.Comment: Two references and one paragraph added acknowledging the fact that
some results were known already. 6 page
Crosscap slides and the level 2 mapping class group of a nonorientable surface
Crosscap slide is a homeomorphism of a nonorientable surface of genus at
least 2, which was introduced under the name Y-homeomorphism by Lickorish as an
example of an element of the mapping class group which cannot be expressed as a
product of Dehn twists. We prove that the subgroup of the mapping class group
of a closed nonorientable surface N generated by all crosscap slides is equal
to the level 2 subgroup consisting of those mapping classes which act trivially
on H_1(N;Z_2). We also prove that this subgroup is generated by involutions.Comment: Final versio
Hierarchies of Manakov-Santini Type by Means of Rota-Baxter and Other Identities
The Lax-Sato approach to the hierarchies of Manakov-Santini type is
formalized in order to extend it to a more general class of integrable systems.
For this purpose some linear operators are introduced, which must satisfy some
integrability conditions, one of them is the Rota-Baxter identity. The theory
is illustrated by means of the algebra of Laurent series, the related
hierarchies are classified and examples, also new, of Manakov-Santini type
systems are constructed, including those that are related to the dispersionless
modified Kadomtsev-Petviashvili equation and so called dispersionless r-th
systems
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