From
one - conetori Hirota ka
toAkiyoshi
two -bridge
conemanifolds
( Osaka City University )
Topology
andGeometry of
Low - dimensionalManifolds
at Nara Women 's
University
October 31 . 2018
Outline
Part
I .
From
once -punctured
torus
to two -
bridge
knotcomplements
(
with Sakuma , WadaYamashita
,)
Part
2 .From
one - cone torusto two -
bridge
conemanifolds
( joint Partly
withYamashita )
Kst
2-
bridge
knots C and links )÷
E Ds
:c iii. :*:: :
" .with leg 's P
't
y & Scp . g) i.
hyperbolic
⇐ =3
⇐sat
SC 5. 2) = C ( 2.2 ) SC 17,77=42,213 )
2%
Hyperbolic
str of 2 - br knotcomplement
- ASWYpicture
quasi
fuchsia
double cusp gp cone sing uppertunnel
TA To
-E
' 'ii :#
Riley. slice me .Le
*
The Ford domains arecharacterized
!!3%
Riley slice
Yamashita
'soutput
ofRiley
slice* There
practical
is a ' 'algorithm
" to checkif
agiven
two -parabolic
group is discrete or not ! !gig
Demonstration I
The ongoing project
Goal :
Replace
the " main cusp " with conesingularity
.:÷÷÷ ÷
for figure. 8.them
The doublecovering space
ofS3
branchedalong Scp
. so ) is the lens space LCP . 8) .5%
Farey
tessellation.
:
to •
Too ÷'s ÷ =
, →• ÷-%
Description of
comb str dueto Jorgensen
÷÷÷÷ ÷
÷
f-
I
dual¥#¥Ft
-w
-Idea of proof
- based onJorgensen
'sargument
*
Jorgensen
characterized thecombinatorial
structures of the Ford domainsfor punctured
torusgroups
.→ s :
⇒
⇒ aI ±u
, a/
Oo
%
Part 2
From
one - conetorus to
two
-bridge
conemanifolds
Steps
onthe way
cone sing quasi fuchsia double cusp gp
at
TT
GO
Ft "
Is
0<10 ① ②
, Quasi③ Additional fuchsia
Today . IT - coneOILS singularity
za 2=2 'T- - - -
Something happens
!!%f
Demonstration 2
Quasi fuchsia
nstructure
[ Moroianu -
Schlenker
, Lemire - Schlenker ]
"
Quasi
fuchsia manifold
withparticle
"( M , -2 ) = ( surface , I fin . ptst ) x R
• all cone
angles
< The• admits
compact
convex coreThin [ L - S ] IF C M ) I Teich C OM )
To oczo a 2T s :
.
" "
. ← o
↳ ①
zJJ ?I
Oo, . ← cone angle < IO soo caFord domain for
conehyp
StrSuppose
⇒CCM
sit . C = glue . .
Choro
ball with cone)
The Ford domain w . r . t .
C
is-
in -
Gl is
cut:*
mmmmlocus want . CI " %
Partial results
Suppose
OC O it(
⇒ oszos za) °
T20"Than I [ A . 20153
Ford
ThmThe••on 2TheTheonT20[Too HRA ,XRspaceFord2018domainhashas]of
domain""good good
thinforfor
any""strcombcombanyis" .fuchsia
. "parametrized
StrStrthin.. " " structurestructureby
the
hyp
Strof
O (compact
convex core ) .,yj
Explosion of
isometrichemispheres
In Demo
2 , r(
isom hemi ) → is as a → 2h - o .• 0=0 ( cusp case )
Explosion
• O > weO ( obtainour occursnewthecomplete
caseat ) D=hyp
2K Str, whereof
2 - bn knot .Explosion
occursbefore
4=21
⇒ Weonly
cannotvia Fordreach domainsthe desired Str③
Employing
Dirichlet domainSeries - Tan - Yamashita studied the extended
Riley slices
, where Dirichlet domain isemployed
."
Surely
, the combStr are same as
those
of
Ford dom for theRiley
slice !! "- said Yamashita
④
Demonstration 3
Dirichlet domain
The
Dirichlet domain w . r. t . p is-
i.
pM -
{
x / ⇒ 2 shortestpaths
•In
. p
Prop
( M . I ) = ( S . I finitepts
} ) x R , coneangle
STGSuppose
. M contains horo balls with cone atboth ends
of
I•
M
contains acompact
convex core{
}
ca⇒ # {
combw . r . t .Strp Eof
I DpKey Lemma for Prop
Lemma Let X be a CAT C- I) space .
Then we have the
following cemeteries
:XJ
ZIHJ
at IW x in e
i
YEt It
Iin
ei
5a , p
ZE
⇒d×
C w . Z ) z d # a Cui . E )%
Choice of
basepoints
Schematic
sectional
Viewsof
Ford/
Dirichlet domains :-2¥
Ls, -21T -Eoµ
O → E 2=217my
- m - O →!
2K - O C- L E 2KN symbolize
theof
"generators elliptic axes
"of slope to
, top forKcp
. so ) .Conj tp
E Zo , the Dirichlet domain w . rt . phas
good
comb Str .Demonstration 4
Some comments
④ The cone
hyp
strfor
thefigure
8 knot inDemo 4 are
studied by Hilden
- Lozano - Montesinosin detail
by using
Dirichlet domains w . r. t .other base
points
.④ Another
family
-for
bundle over S ' -is studied
by Jorgensen
, and Heusen er --
Ponti Suarez
- .④
The families for figure
8 knot arealso
studied by
Thurston .¥