Constant Mean Curvature n-noids with Platonic Symmetries
Constant Mean Curvature n-noids with Platonic Symmetries
复制标题
具有柏拉图对称性的恒定平均曲率 n-noids
DOI:
--
复制
发表时间:
2007
期刊:
影响因子:
--
通讯作者:
N. Schmitt
中科院分区:
文献类型:
--
作者:
N. Schmitt
W econstructfam iliesofgenus-zero constantm ean curvature(CM C)surfacesin R with nitesym m etry groups. The construction isvia the extended W eierstrassrepresentation forconstantm ean curvaturesurfaces.A description ofthisconstruction (Dorfm eister-Pedit-W u [5])can befound in [12], brie y in section 1, and elsewhere. The construction for im m ersions into R is outlined as follows. (1) W rite down a potential with values in the sl2-valued loops on the -param etrized unitcircle S and certain m erom orphicbehaviorin on the unitdisk. (2)Solve the equation d = .(3)LetF bethe unitary factorin the Iwasawa factorization of . Then F isthe extended fram e ofa localCM C im m ersion. The im m ersion can beobtained from F via a Sym form ula. Theendsoftheim m ersionsare conjectured to beasym ptotic to half-Delaunay surfaces, becausetheirpotentialsare localperturbationsofDelaunay potentialsattheirends. Sincetheconstruction oftheim m ersion involvessolving a di erentialequation which has m onodrom y,thedi culty oftheconstruction isto closetheends.Thisam ountsto showing that the m onodrom y representation is pointwise sim ultaneously unitarizable on the unit circle via conjugation by a dressing. The unitarization problem for the im m ersions in this paper is solved by reduction to the trinoid case,which is solved [12]. The idea is to im pose sym m etries on the potential in such a way that the fundam entalpiece ofthe surface has at m ost three points ends. A m odi cation ofthe trinoid technology for non-closed surfaces then shows that under a suitable setofinequalities,the m onodrom y forthe fundam entalpiece isunitarizable. The m onodrom iesforthe whole im m ersion are powersofthe m onodrom iesofthe fundam ental piece,so thatthe m onodrom y group forthe whole im m ersion isunitarizable. M ore precisely,the above program is im plem ented as follows. W e construct a rational m ap u :P1z ! P 1 u togetherwith a potential on P 1 z such that descendsvia u to a potential on P1u which has at m ost three poles at the branch values ofu. This is accom plished by taking u to be an invariantof nite group ofM obiustransform ationsacting on P1z.By trinoid technology,thesphericaltriangle inequalitieson thelogsoftheeigenvaluesofa set ofgeneratorsofthem onodrom y group im ply thatthem onodrom y for isunitarizable.The gauge equivalence between and then im pliesthatthe m onodrom y for isunitarizable. Itfollowsthat inducesa CM C im m ersion ofa punctured Riem ann sphere. Since the astronoid construction isbased on the trinoid construction,m any ofthe tools have already been developed [12]. The paper starts with lem m as on on nite sym m etry groups and invariants,and on m onodrom y for potentials and their pullbacks. section 5 solvestheastronoid m onodrom y unitarizability problem ,and theastronoidsareconstructed in Theorem 5.7. The rem ainder ofthe paper is concerned with sym m etry. Theorem 6.5 shows that the sym m etries of the potentialinduce sym m etries of the CM C im m ersion, undersuitableconditions.Thesym m etriesoftheastronoidsarecom puted in Theorem 7.3. Ithank Franz Peditform any helpfuldiscussions.
影响因子:
1.8
作者:
M. Kilian;W. Rossman;N. Schmitt
通讯作者:
M. Kilian;W. Rossman;N. Schmitt
DOI:
--
发表时间:
2006
期刊:
Ann.della Scuola Norm.Sup.Pisa 5
影响因子:
--
作者:
W.Rossman;N.Schmitt
通讯作者:
N.Schmitt