3,132 research outputs found
Goethe Faust II, Die klassische Walpurgisnacht : eine phantastische Folge in zwölf Blättern / von Bruno Seener. [Vorwort: Felix Zimmermann]
No full textGOETHE FAUST II, DIE KLASSISCHE WALPURGISNACHT : EINE PHANTASTISCHE FOLGE IN ZWÖLF BLÄTTERN / VON BRUNO SEENER. [VORWORT: FELIX ZIMMERMANN]
Goethe Faust II, Die klassische Walpurgisnacht : eine phantastische Folge in zwölf Blättern / von Bruno Seener. [Vorwort: Felix Zimmermann] (1)
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Title page (3)
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Vorwort (7)
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Brief von Bruno Seener vom 22.05.1922 (33)
beigelegte Zeichnung (37
On large groups of symmetries of finite graphs embedded in spheres
No full textLet G be a finite group acting orthogonally on a pair
(S^d, \Gamma) where \Gamma is a finite, connected graph of genus g>1
embedded in a sphere S^d of dimension d. The 3-dimensional case d=3 has
recently been considered in a paper by C. Wang, S. Wang, Y. Zhang and the present
author where for each genus g>1 the maximum order of a G-action on a pair
(S^3, \Gamma) is determined and the corresponding graphs \Gamma are classified.
In the present paper we consider arbitrary dimensions d and prove that the order of
G is bounded above by a polynomial of degree d/2 in g if d is even and of
degree (d+1)/2 if d is odd; moreover the degree d/2 is best possible in even
dimensions d
B. Bligny. Saint Bruno, le premier Chartreux
No full textZimmermann Michel. B. Bligny. Saint Bruno, le premier Chartreux. In: Revue de l'histoire des religions, tome 203, n°4, 1986. p. 446
Bounding and nonbounding finite group actions on surfaces
No full textAbstractWe consider the problem of which finite orientation-preserving group actions on closed surfaces extend to compact 3-manifolds. A solution is known for cyclic, dihedral and Abelian groups. In the present paper, we consider actions of the linear fractional groups PSL(2,pn). Our main results imply that, for primes p≡1mod4, all actions of the groups PSL(2,pn) bound compact 3-manifolds. In particular, we show that all isometric Hurwitz and genus actions of these groups on hyperbolic surfaces bound geometrically, i.e., extend isometrically to compact hyperbolic 3-manifolds with totally geodesic boundary. On the other hand, for all primes p≡3mod4 there exist nonbounding actions of PSL(2,pn)
On the mapping class group of spherical 3-orbifolds
No full textWe classify finite group actions on the 3 dimensional spher
On topological actions of finite groups on S^3
No full textWe consider orientation-preserving actions of a finite group
on the 3-sphere (and also on Euclidean space ). By the
geometrization of finite group actions on 3-manifolds, if such an action is smooth
then it is conjugate to an orthogonal action, and in particular is isomorphic
to a subgroup of the orthogonal group SO(4) (or of SO(3) in the case of ). On
the other hand, there are topological actions with wildly embedded fixed point
sets; such actions are not conjugate to smooth actions but
one would still expect that the corresponding groups are isomorphic to
subgroups of the orthgonal groups SO(4) (or of SO(3), resp.). In the present paper,
we obtain some results in this direction; we prove that the only finite, nonabelian
simple group with a topological action on , or on any homology 3-sphere, is the
alternating or dodecahedral group \A_5 (the only finite, nonabelian simple
subgroup of SO(4)), and that every finite group with a topological,
orientation-preserving action on Euclidean space
is in fact isomorphic to a subgroup of SO(3)
On the determination of knots by their cyclic unbranched coverings
No full textWe show that, for any prime p, a knot K in is determined by its p-fold cyclic unbranched covering. We also investigate when the m-fold cyclic unbranched covering of a knot
in coincides with the n-fold cyclic unbranched covering of another knot, for different coprime integers m and n
On minimal actions of finite simple groups on homology spheres and Euclidean spaces
No full textWe consider the following problem: for which classes of finite groups, and in particular finite simple groups, does the minimal dimension of a faithful action on a homology sphere coincide with the minimal dimension of a faithful, linear action on a sphere? We prove that the tzo minimal dimensions coincide for the linear fractional groups PSL(2,p) as well as for various classes of alternating and symmetric groups. We prove analogous results also for actions on Euclidean spaces
A note on finite group-actions on surfaces containing a hyperelliptic involution
No full textMotivated by the analogous problem for hyperbolic 3-manifolds, by topological methods using the language of orbifolds we give a short and efficient classification of the finite diffeomorphism groups of closed orientable surfaces of genus g > 1 which contain a hyperelliptic involution; in particular, for each g > 1 we determine the maximal possible order of such a group
Some results and conjectures on finite groups acting on homology spheres
No full textAbstract. This is a note based on a talk given in the Workshop on geometry and topology of 3-manifolds, Novosibirsk, 22-26 August 2005. We consider the class of finite groups, which admit arbitrary, i.e. not necessarily free actions on integer and mod 2 homology spheres, with an emphasis on the 3- and 4-dimensional cases. We recall some classical results and present some recent progress as well as new results, open problems and the emerging conjectural picture of the situation. We are interested in the class of finite groups, and in particular in finite non-solvable and simple groups, which admit actions on integer and mod 2 homology spheres (arbitrary, i.e. not necessarily free actions), with an emphasis on the 3- and 4-dimensional case. We present some classical results, some recent progress as well as new results, open problems and the emerging conjectural picture of the situation. 1. Basic problem. Which finite groups G admit orientation-preserving smooth actions on certain classes of manifolds: spheres Sn, integer homology spheres, mod 2 homology spheres (i.e., homology with coefficients in the integers Z2 mod 2). We consider only orientation-preserving, faithful, but not necessarily free actions (in general, the free case is classical, the main new results presented concern nonfree actions). Particular emphasis will be on dimension three. We note that every finite group admits a free action on a rational homology 3-sphere [4]. Also, any finite group admits a faithful orthogonal action on a sphere (by choosing a linear faithful representation); on the other hand, the classes of groups admitting free actions on integer or mod 2 homology spheres are very restricted. The most important single case is that of the 3-sphere. If an action of a finite group G on S3 is nonfree then, by Thurston’s orbifold geometrization theorem, it is Zimmermann, B.P., Some results and conjectures on finite groups acting on ho-mology spheres
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