Fwbenius Manifolds
1
. \
March , 2nd , 2018 .
1
•
History of
Fwbenius- Manifolds i~ 1980 , Saito 's
singularity Theory
~ 1990 , Vafa 's Quantum Cohomology ( A - model 1
"
Moduli " of C-Y Holds ( B. model )
(1) (19941 Dubrovin : of ZD
Geof
TFT ( textbook 1I
PDE :
eqns
WDVV(2) ( 1998) Manin : Fwbenius Manifolds , Quantum Cohomology and Moduli Space
( Gwmov - Witten
Theory
)(3) ( 2004 )
Hartling
:Fwbenius
Manifold & Moduli Space furSingularity
.MainQuestio=
:Analytic
Continuationof Fwbenius
Mfds?
Compact
Example
? (Compaocitication
? ? )Definition
Fwbenius
of
Manifold :@
-
M : C ° . mfd g: TMXTM - IR " metric " ( not necessarily positive def , only require non .
deg
.)commutative
A
multiplication
Str : o : TM×TM - TM .In
any
local word Ix', ... , X"l , the basis { Jj:=÷xgl
on TMlu
,We denote The Str crust ,
Jjo
2k = CFk
2m .They satisfy
:(1)
g
13 flat i.e,Riemlg
) to . Therefore , 7- flat word , Lt'' ... it " 1sit ,
9abi= g(2a
, 2b ) are constants(2) Ze : M → TM : identity 1 unity section . st . eoX=X . HXETM
T
global
section(3)
GIXOY
, Z ) = SIX , YOZ ) Define cc X. Y ,Z ) :=9( XOY, Z ) :totally symmetric
totally Lo, } ) - tensor
→ 2;
o2j
=glkcije
Jk Cijl : symmetric wire . iijik .(4) V :L - C connection
Nxc
Wirth g ) ( Yiz , W )EPYC
) (X, ZiwlRegard
PC :C 0,4 ) - tensor Then aboveidentity
:totally symmetric
!→ This is the
associatively
of 0(5) 7e=o
Rink: Later , we will introduce the Euler
vf
. EIn flat word ,
Hillel
we may assume that e=2¥
,
=
(4) becomes :
|2aCb_cd=2b_Cqcd_
Calculus ( ! ) implies i I ( Ioc,)fcn
f- It ', ... , -01 st . Cabo=g?[§µ-yqt
→ The function F determines everything on The Fwb. mfd i Metric i gl . ,. 1 -
gleo
. , . ) = c (e, . , . ) ⇒ Gab =Iffy
Str const . of
multiplicative
Str : Ckij =gklg.fi#yq
→ Cikj : functionof
F .Associativity of
0 : ( JiJj
) ° Jk =;
Jio ( 2jo 21<111
Kfj
2eo2k ) 2i . (Cjtkael
"
"
£
Cijcek
as 2ciecglk
as(
Witten -Dijgraaf
- Verhhde - Verlihde )lis lis
Edicts
- ( i) WDVV eqnIII
"
IIIIEimm.int#es
Cotati : FindWDVVa wordeqn ,Issue only
- free timeexpressionin flatfor wwd .WDVVEI ICE-f.fr
Theo=÷eb| ftp.cpab.cdpbcpae/+Cpae(
existenceCpdacpef
of -potential Cpdfcpae
)F - ⇒tff
"3k¥
.2k¥ )
+ c .
total
.epaulet :flY!a÷
.Ethanol ;t÷Y÷al
-campsite
-
fare
2Eb
)
⇒
(
cpda¥5
+cpdiscfeta )
-( cdp.tt#+cdpt2claeb- tangled )
+( deg ¥ ;
-Claim
: 137 holds ingeneral
wwdisystem
(Xi) ( } )Exert
: (a)Verity
the claim( b)
Heveling
(. Manin ) . (3) is the word .expression of
Thefollowing
: KY .Z e PCTM ),hx
. , , LZI=Xohylzl
+ Lx l ZIOYStill form another
of WDVV :y
X'T extends torf
.Li TM → TM llil ) - Tensor ie , a vector - valued 1- form .
Torsion
of L
:TLCXIY
) := [ LX, LY ] - L 1 [ LXIY ]) - L 1[ x. LY]|+L2[
KY ]Hantjes
tensor :HLCKYI
:-.TLILXILYI
-LTL
( LKY ) - LTLCX .LY ) +,
for
XIY : vectors L ' TLLKY )Now , for XETM ,
Lxl
'll =XOY
⇒Lx
: TM → TM X: uf.
Exerts
:HL×
to ←→ WDVV eqn .Example from Singularity Theory
I Saito)
:Surface
Singularity
:flxiyiz
) =xIy2tp(
2-1=0 in 1 3pA ) =
Z5ta=3Z3t A±Z2ta±Zt a±
:deformation
of A4 -Sing.-
ry tmodwloiratpaaornaumueptero
An sing :xtytznt
'=oAs-sing.
←dim
,cA=4
iso .sing
.A =
QKXIYIZD /
(completefx
,fy ,fz
intersection) = 1 [Z]/(
I 'cz)) I 'lZ1=5Z4t 3A} Z2t2azZt a, PLZ), qcz) EA . plz ) 0912-1 =p ( z) . qizl ( mod 'LZI
))The is
given METI by
Gwthendieuk 's residue :RmIi 0 - complete intersection
dimt
A= KKZI .. .iZmD/l fi ,.. ,fm1 finite -di n 't k - Us.( say k - ¢ )
I : A →
tree
K mapydfin . ..
ndtm )
c- &.YEA , IC 41 :=
Resfm=o Resfm
,=o- - ' ''' '
Resfeo ( FTIFN
It B a trace i. c .
gcaib
) := Icab ) - isPldjnon)9141.degi Exert
: (a)Show
Thatglpizhqizsl
=IT II
(b ) The metric is flat in
R4
take K - IR ) , withds2=
daodaz
+ daidaz -3pA
}daadas
-st azdaj
to = Ao -
¥
Azaz Write down :The flat Wd '
|
, ,= a,.÷aj £u°¥s=CFj÷tk
tz = Az
tge
A} 11March , 9th , 2018 .
• WDVV with Euler vector field i
n
f- It ) = Flt ',....
, tnl : potential Capr =
2£ prf
T= [tie
;2=1
1) 7 xp :=
Cup
is a constant , non .deg
. matrix ( metric )C
Ip
= 7 "Ceap
:"
Str const .
"
21
Associatively
: ea. ep =C%Hler
B a ring At , with unity e,Then led.ep ) . er = ex . (ep. erl ⇒
§
CasesCsf
=§ Calscpsr
→ WDVV eqn3) Additional "
quasi
-homogeneity property
" :require :
deglt
) = I ,deg
I e. 1=0 ( so,deglt
' 1=1 ) t=t' eit that ... . + thenNotation : da :=
deglt
'1 9ai=degledj
= I - daRecall ; F:
weighted
homogeneousof degf
=D # means :F (cd 't ,,
cd2tz
, . . . ., cdntnl =Cdffct
, , fce 1 *|
§=£dlf¥
, Eh , =↳ § datba
, 2amIT
,)
The case :
we only care about Bnp, F
, we require only :
e=¥
.EHl=daT£2a
|£
,"for" someLef
=wristdff
.df
+ ,Aapt
Adp, Ba'tf
, C+ , Batwith 't CEuler -vf
*, ') £EeI[ genteel
EH
)
=§g
(9ftp.rd/2as.T
.Lee
= - d. e -(
Quasi-
homogeneity
property-nLemmal_
:
KEY )&p
= 1df
- di)9xp
i. e. E is an infinitesimalconformal tmnsfi
Wint . The flat metric < i ) = (Map)
Rinkh : conformalwuformal
transfi
isgenerated >/3i
in Euclideanby
: isomethyspace;
: , h=2dilationconformal, inversionTransf
. (, Lionvilleiff holomaphiz
,cf
,Dubrovm , Fomenko , Nouikov UOLI )
pfi Apply 2p2a2
, to C *I and do the wmmutator with E.2p2a2EF= df 2p2x2f
=dfY&p
observe : 2. EF = [21, E] Ft EZF = did , ft E 2. F ⇒
2p2£2EF=di7apt2p2aE2iF
Jp2aE2
, f= 2ps ( [ 2£. E) + Eda ) 2iF = 2p(99
2p2, f) + 2pE2£2iF⇒
dfrlap
=diyxp +997Pa
+ Efs 7PaCd : If 4,, =
Mleiilil
= 0 , and Q= ( 9fs) has simpleeigenualues
, thenby
a linearchange of
word, , we may assume :Map
) = (I
...f )
, and thenFlt ) =
Itt 'I2tntIt§nt
't at " " + fltz , ... .tw )Also , for d ,==l , 91=0 , qn :=d ,
df
= ztdn = ltdat dnti - a =3 - d→ %a + 9 one ,, -a = 2- ( da + dcnti , . a ) = 2- (2 - d ) =D .
pf
: Lei ill > =o ⇒ Can chooseeigenvector
enof
Q sit. ( e, .eu > =1Now , on span
Seiienlt
, can use Q -eigenvector
to get (A) . ( Check IRink : In
general
, if Q isdiagonal
izable , ThenEHI
can betransf
. (by
alinear
transf
.1 to :Ect ) =
§dat&2&
+[7
r22a12162=0}
.
Example
:1 , n=2 , WDVV B empty ,
Scaling
conditions ⇒I) Flt , ,Tz ) =
lztitz
+tzk
,k=[d1
dtl , 2,3 , D=deglezs
.iii Fltiitz ) =
ftp.tzttz2 logtz
, D= - Iiiil Fltntz ) =
Itptz
+lugtz
, d =3iv ) FH , ,tu ) =
Ititz
+e£
" , D= lirtoV) Flt , ,Tz) =
ftp.tz
, del , r=o .2, n=3 , Fit ) =
It its
+It
,tit fltzits
)WDVV ⇒
flxiy
) satisfies f×2×y =fyyy
tfxxxfxyy
pf
: multiplicative table : 4=l , ez , e3 (Yap)=/
, ,1
)
e
}
= Fzz, 7 " e} + fzss)
"
e, +
Fussy
" e, = es +f×××
ez +fxxye
,es. ez= Fzs, ez + Fsss e2 +
Fs33e|
=fxxyez
+fxyyel e5= Fzz
, ezt F 33202 tFzzzei
afxyyezt fyyyei
Associating
( WDVV ) ez:(. ez) .e } = ezlez . e} )⇒
ejtfxxxez
.eztftxyez
=ftxyeftfxyyea
⇒ z +
fyyye
, +fxtxfhxyezt Westside fxx\yez tfxyf fttxftyyei Rft
= t ()ez+t2××ye
# ,( Check)
Scaling
conditions : (al ( I -f) xfxt
(I- d)Yfy
= ( 3- d)f
of#
,z , } .Cb) d=l :
lzxfxtrfy =2f
( c) d=2 :
rfx
-yfy
=f
(d) d =3 :
lzxfx
+zyfy
= const .idea_i
Use thefirst integral of
EHI , will do case ( d ) :Question
:Find
agood
, word , system ,vf
. on the I Ky) - plane . (zx
, 2y ) i. e,{
X's
I×
y'=
ay
⇒
|×=c,ez±
Y= Cze "
Define 5=7×4
B a const ,along any integral
curve . We set5=4×-4
t=xgx=t y=sE4
Change of
Variable :ftfcxiy
)=3¥ .TT +2¥
.}Iu=f×+4t3sfy
=
I
(Ix2×t2y2y ) f
⇒staff
= ( ⇒ft=2÷
⇒fezclogtiocs
)⇒
flxiy )=2cl°gx+
011×14)
- L * * 1Thm_ iflky
) satisfiesflixy
=fyyytfxxxfxyy
can be Transformed into ODEof ¢e¢lZ
) via L**14" ' =
400412+32 c¢"
+11202-0114 "t 7842-2
@" 2+16 czd"f16oz2¢ 'd
"'t1922301
,"4
"This B a
special
case .of
Pain level It ( as well as all other n -3 cases )• Card .-
free form of
Euler v.f.
: EEPLTMII- THE ) =0 ( This make sense since Map B flat )
- Q - OE is a covariant const .
operator
⇒Eigen
valuesof
Q areconst ,
fans
on M , sit,
Meta Lee :c
= - e:
herfap
=D Mapfor
some unst . D.March , lbth 2018 .
•
Symmetry
of WDVV :Type
I :Legendre
- Type TransformationSa
17<=1 ,. . .in ) : Courd ,change th £
' sit , LalIr
=2r2xFHi
(b )
Fpiwtt
) =FµrH
)( c)
ftp.
=Yap
( i )
2a=s÷I=2j[÷a÷÷p
=gBr2aa< =7 jrfctsttfp Farr
"Jp
=Ffa Jp
Cd
:If
2x . is invertible . then?a=2x
.In
. Inparticular
,2<=2×2^2
⇒ 2x=e .pf
: =FLA 22.2¥ Ip
' 2k . LetGx
be the inverse matrix for 2z . :GIs
,FI
, 2x = 24"
GXI
,Fla Ip
- 2x =Jai
2k .RMII
: Sx 's commute furdifferent
K 's. S, =identity
. So, at the end ,we need eo
renumbering
the indices to switch K c- 1 .(2)
2£Fµv=7PrFaxr2^p Fair =9Pr
Faxrfair
=Ffa Fair
11
F£µv
⇒ Under t ' →
It
,Far
=Ffa f§µnj
13 )
Preserving
WDVV eqn :Iggy fi×kfµg,g type
= F " "Feig
⇒WDVV
inoriginal
word . system.II ; IIR IIR EE 'a
Examples
: ln=2 , del , r=2 ) F =Itt
')2t2+ et Yap =/ T! /
7<=2 ,
Sa
: I '=ta
= Faz = et ' check that ;ELE
',.i2j
=IF
'# It 's
LE't
f2= I
, = F ,z= t 'Uogf
' -E)
, Then switch 1← ' 2 .
Elf'iE2j= 's FZIF
's' eICE 92
(1.get
3121→ The case D= -1 ,
Rink
:If
9x, = .. ".=9xs
, thenfc=Ld
. . . . ., Cst . can considerSc
:I
. =§
,ci2&Jx ; FHI =) So is a transf ' if Ci2x ,. B invertible ,
Type
2 :The
InversionI
I
' ='s two Ed=¥I
for a # 1. nIn
.tn/ffYpIyEyHlf4
' -that 'l=einif+ ÷ # tie
It B
conformal
:okpdfddff
=Tqn 'T
72psdttdets
Effect
on Euler vuf . ( Dubnvm Lemma B. 1).Exercise
: 542 ;¢ ) acts on solhof
WDVV eqns with d=l .t ' - t 't
I ok §
,tat . t " →
t%tn+d
) x±linqn - ( At
"tbY(
ctntd )• 1- dimll
affine
connection '- reallcpx
D#i
This Bgiven by
a function ret ) =title
) sit . onk
- formR•£
:fdtke Rok
,Of
dtkt ':=(f¥
- Kmt ,f) dekt
' - ( *IIn E :
fltsdtk
=( fit
) (dt1dF1k1dFk-i.fTF1dEk-HIe.triEiF1dEkH-ldfedalfTEKEIlkl-krrhfTFllfElY-dHfEtfiEtktEyaEElktlEjktis_feYdekalFelYtii4dE1dI-TransformatinruleirLEl-YfI-C@d2Igfddg-CtxiMiie.g.E
.EE#adI=Eibd=e*aediE=-KTtdj3
⇒
FLE
) =( Cttdprlt
) +2C ( Cttd )No local inv . :
Locally
,May
solve :w=¢df
sit . 0w=o i. e.¢
'
-
84=0
Then
we set : w=¢dt= :d× × : flat parameterNotice that LH) reads as :
of dtkt
' =dkadqlfofkjdzktt
Def Projective :( Structure )
1- dim
't attire
connectionwl Mobins Transformation
assymmetries
B called a
projective
Str ,Prof
: 4)Rdt
' ..quadrate differential
,R=£T
-IT
is an inv.under Mobius
transf
. ( cheek )(2) t can be reduced to 0
by Mobius transf
, #R=o
pf of
( 21 : ( ⇒ ) trivial C ⇐ ) reo ⇒day
-
II r2=o
2dy÷=
dt ⇒ 2
fdtf
= T - To ⇒ - 2f-
= T - To ⇒ r=⇒
.Now
, setI
:=#
,⇒
FLEI
= -21T - To ) + LLT - To )=0a
Rmk_i Recall That
moduliof flat
connection < →{
rep .of
Ti ( Xix )t
⇒
No local
MV.EXamp1e_ : L = - doxt, + Ulx ) on D= S' or ICP'
Ly ,=Lyz=o
Set T=¥11
-projective
Str . !( Ioc .) as our new local word ,
The non .
trivial attire
connection isdefined
sit , X=flat
word ,⇒ Rdt ' = zudx . l
Check
)g fixed k
Exercise
iplr.rs
. . .. ) :poly
. sit ,pdtk
is in. under Mobiustransf
frrany
attire to , then pe QI Ri VR , ON ii. .., 1 , where Q B agrd
homogeneous0k
has degree
CHAZY Eqn
: 3d Fwbemus Chart with D=93=1
, r=o . E = t'2
, +It
222 to 'Ask for Solis of
WDVV ,periodic
in t3 . period =L ,analytir Hit
it3)
= 10,0 , inF hit
'it4
=}EY2t3t I eilltl
' .¥5 'rlt3
) ,rtl=n§ anq
".q=e2
'T 'tWDVV eqn
becomes : 8"
=
brr
' -9
r'' 1of
. 1.13 Cbi )Exert
: ruleIjl (
1 -249-7292-9693
. . . .Trettin e.)
d=l ,
Sllzilc
) acts on the ODE ! ⇒Fits
into thetheory of affine
connectionsEqns from
QIR , OR , ....0kR1=o R= drlde
-IV
setu=I #
2,R=dr/dI
-IV
where w=dxSet U=
's ¥2
, where W=d× ,0w=o 7w=oL= -
ftp.ucxl
yilx⇒), yzlx ) normalize Yi , Yzby 1¥ Yy
,}|
=/t.br/y.~sr=dYh=#l
' sincehe
.www..gl
.Leo
, R=ok=1
, 71=0 ⇒ r ".3rr'
+r3=o
k=2 ,
82ft cN=o
for some CIF
y
'"
- brr
"t9r
' 2 +(
c . 121(
r' -It "F=o
CHZ givesChazy
eqn !In terms
of
u, the eqn d u"t2cu2=o
Observation
: p'2=4p3
-gzp
-g
} ⇒ 2ps"p
' =L'2p2p
' -gap
'=) p " =6p ' -
92/2
Thus , 92=0 ,
93=1 U=±oPol×
)Poieqni
- an - harmonize ellipticfunction
.←
malizeODI
Lame
' eqn y'' t ( Apt B) p=oy
" +I
polx)y=o
Let t=l -ppcxi
, weget
:tcttlddtte +1ft
-f) date *
=oMarch . 2
3rd
, 2018 .
ZD
Topological
fieldTheory
(Atiyah
's axioms )1 , Space of local
physical
States A i. e. dine A =n < is2. T[ , J{ I :-) Vee A ( s ,
St
as , := ¢ ,if
22=4 , [ : connectedcpt, oriented surface
|
, if Ci has orientation,
#
Ai ,Ai=|
Aa* induced from E .if J{ acid .Ci... IasCk' i 'F not ,
⇒ K¥1 ,¥ a- Alqyz
YE, as 1 e , = A*aA*oA=Hom
( ADA i A)Also
, we require Theassignment
is a Top. in . i. e .They
are the sameunder Aomeo.
÷
) normalizationit
:DID
, ideA*
@ A2)
multiplication
: Vs, # sz = vs, 1 Vsz} ,
factorization
:j(¥#y Ying ¥¥"
ST
Vs, C- A •
A*o
. . ". Then Vs = contractionof
vs, along The#
•Genus g
, s - pt wrrelator : cut .vgis
:=HQ.PE#M*genus=g
symmetric function@ satrnof
• ⇐ v
of Da
genusa) a-
0 e.A*•A*oA=HomlAoA
, Atgives
thealge
. Str.•
y
:= Vof III.
eA*bA*
i. e,y=
Vonsymmetnl
pairing. e := v
of
a cap ( disk )g§n
e AThai lciyie
)gives
A aFwbenius age
, Str( primary
chiralfields of
thetheory
)pf
:Associating
:(L*p)*r =L * ( p*r ) x. p, re A.a
Ml
a1¥
€.
.tn#.r
-e¥n↳r
g=o
Unity
: Cut andglue
a disk = donothing
Non .
degeneracy of
y :Let
F
:= vof (f=§
Then observe thatDy¥=%
⇒
n5=id AI¥ ¥1
⇒ y ; invertible
Fwbenius Property
:ykxpirl
= Vo,}Hip
, r ) viag$[YpIp 4mL .hr ;
.Rink
: This useonly
Thegenus
0 part !Actual Physics
consideration :QFT on D din 't
-
mfd [Data : • A
family
of local fields ¢& (x ) XEE• A
Lagrangian
L =L ( 4,10 :$ ,"
... .
)
→
S[
¢]
=|zL( 4,41
, ... . ) :~ action involves metricGijcx
).
Quantization
viaFaymann
'spath integrals
:partition function
: 2 £ =f
[ d¢]
e- {(¢]f :-. The spare
of
t( an fields ) " measure "
- sc ¢ ] Correlation functions : ( 4dLx),
¢piy
), ... .7g
:=)
[d¢]4&(
x )dpcy
) ... .. Es
The classical
they
isconformal if
fS=o , forany 8Sij
=Egij
topological if
85=0ffgij
TQFT : The correlation function depends only on the topo . on { , not on
it XIY, . . .
< da
,¢p
, "-7g
←genus
Now,
for
a TFTarising
from TAFT ( or a TCFT .if integrable
over all wnf.May
considerdeformations
preserving the top. ihv. Li → [ + Ettha .classes of
⇒ Moduli space L local 1 E)
Method
: QFT withnilpotent
symmetry Q : H - H ←Some
Hilbert spaceof
chtarge 62=0 States
Observables '' = operator on
H
which commutes with Q i. e.{
Q,41=0
5
Q - cohomology on all operators : 22 - bracket
By
22 -graded
Tawbiidentity
: | Q , Said{10,011+-101.541}=0 }1±|Q
,⇒
{
a. s a.0111=0
°Define : A =
kerclfimce (
Theprimary
States fields )' : Q is a
symmetry
⇒( {
0,4 }, 4, .dz, ... .1=0
LAI