Introduction to Topological Strings on Local Geometry
Masato Taki/ YITP, Kyoto University
Lecture @ 国家理論科学研究中心 15, October 2010
瀧 雅人
/
京都大学 基礎物理学研究所Topological Strings
Today we will study topological string theory (on the so-called “local geometry”).
It is a solvable toy model of string theory, and has many interesting mathematical feature. So, topological strings give a theoretical playground for string theorists.
∗
∗
∗
dualities relates many physical & mathematical theories solvable model for string theory
non-perturbative dynamics of gauge theories Moreover this theory is a toy model of varied applications.
topological strings
curve counting
Chern-Simons theory matrix model
Seiberg-Witten-Nekrasov theory Dijkgraaf-Vafa theory twister string
Math Physics
Applications
knot theory
black holes mirror symmetry
Calabi-Yau compactification
. . . . . .
・ Hori et al , “Mirror Symmetry” , Clay Mathematics Monographs
・ M. Marino, “Les Houches lectures on matrix models and topological strings”, hep-th/0410165
・ M. Marino, “Chern-Simons theory and topological strings”, hep-th/0406005
References
・ Vonk, “A mini-course on topological strings”,
hep-th/0504147
・ Worldsheet formulation of topological strings
・ Conifold and geometric transition
Plan of the lecture
・ Geometric engineering of gauge theories
・ Application to AGT relation
Part 1
Part 2
Calabi-Yau compactification of superstring theory is an important topics in string theory.
1. Worldsheet Formulation of Topological Strings
- Why Topological String Theory
superstring theory (heterotic,
Type II, ...) on M × R4 gauge theory on
N = 1, 2 R
4The low-energy effective theory of the Calabi-Yau compactification of Type II A(B) superstring theory ??
Topological sting A(B)-model captures the holomorphic information of the low-energy theory exactly !!
In general it is very hard to compute stringy corrections on such a curved background.
So, you will get exact result about stringy correction if you can compute topological string theory.
In this lecture we study topological strings propagating inside a CY. So we define it at the beggining.
- Calabi-Yau space
We impose the Kahler condition
X
i, X
¯ii, ¯i = 1, · · · , d
Let us consider a complex manifold
d dim
C(= 2d dim
R)
dω = 0
forω = i G
i¯jdX
i∧ dX
¯jThen the Calabi-Yau condition requires that the Ricci curvature of a Kahler manifold is flat :
c
1(M) = 0
R
ij= 0
- Calabi-Yau 1-fold
T
2Torus is a simple example of Calabi-Yau 2-fold.
X
1= z X
¯1= ¯ z
z ∼ z + 1
- Calabi-Yau 1-fold
T
2α
β α β
[Σ] = pα + qβ ∈ H
1(T
2, Z)
There are two basic 2-cycles .
Generic cycles are spanned by these two cycles as
- Calabi-Yau 3-fold
The Calabi-Yaus of our interest are 3-fold . Moreover we deal with
only non-compact cases.
d = 3
conifold : hypersurface inside
x
2+ y
2+ u
2+ v
2= 0 C
4S
3S
2xy = uv
By changing the coordinates, we have another difiniton eq.
t
Let us recall that string theory is a quantum mechanics of one-dimensional objects propagating the target space M. A string sweeps out the two-dimensional surface which we call “world-sheet”
- String Thoery
string
worldsheet Σg
M
t
Let us recall that string theory is a quantum mechanics of one-dimensional objects propagating the target space M. A string sweeps out the two-dimensional surface which we call “world-sheet”
- String Thoery
In order to formulate topological string theory propagating inside a target space M, we consider holomorphic embedding of the worldsheet into a Calabi-Yau M.
X : Σ g � → M
X :
X : Σ
g→ Σ ⊂ M N
g,Σ “number” of holomorphic mapsF g = �
Σ∈H
2(M, Z)
N g,Σ e −t
Σt Σ
Kahler parameter (area) of 2-cycleΣ
- Mathematical “definition” of topological strings
X :
X : Σg → Σ ⊂ M
Ng,Σ maps
F g = �
Σ∈H
2(M, Z)
N g,Σ e −t
Σt
ΣΣ area - Mathematical “definition” of topological strings
Z(t) = exp �
g=0
(g
s)
2g−2F
g(t)
2D nonlinear sigma model whose target space is - Physical realization of topological strings
N = (2, 2) M
topological twist
(redefinition of the Lorentz charges) topological sigma model whose target space is
M
[Witten, ’88]S
A=
�
Σg
d
2z √
gG
i¯jg
µν∂
µX
i∂
νX
¯j+ i�
µν∂
µX
i∂
νX
¯j+ · · ·
we can model the mathematical definition (curve counting).
X
i(z), X
¯i(z)
ρ
iµ¯(z), ρ
¯iµ(z)
scalars on
Grassmannian one-form on
χ
i(z), χ
¯i(z)
Grassmannian scalar onΣ g
Σ g Σ g
The action of topological sigma model whose target space is is given by
M
This action is BRST-exact for a topological symmetry Q
S
A= {Q
BRST, V (X, ρ, χ) } +
�
Σg
X
∗(ω)
V = 1 4
�
Σg
d
2z √
gg
µνG
i¯j�
ρ
iµ∂
νX
¯j+ ρ
¯jµ∂
νX
i�
[Q, X
i] = 0 {Q, χ
i} = 0
{Q, ρ
iz¯} = 2i∂
z¯X
i+ Γ
ijkρ
jz¯χ
k�
Σ∈H2(M,Z)
e
−α�1 tΣ�
[X(Σg)]=Σ
DXDχDρe
− α�1 {Q,V }Then the path-integral is
topological : independent of and worldsheet metric
α
�Then the path-integral is dominated by the minimum
≥
�
Σg
X
∗(ω)
Let us evaluate at
α
�→ 0
∂
z¯X
i= ∂
zX
¯j= 0
The path-integral localizes to the integral over the holomorphic maps !!
S
bosonA= �
Σg
d
2z G
i¯j(∂
zX
i∂
z¯X
¯j+ ∂
z¯X
i∂
zX
¯j)
= 2
�
Σg
d
2z G
i¯j∂
z¯X
i∂
zX
¯j+
�
Σg
X
∗(ω)
X : Σ
g→ Σ ⊂ M
we count“number” of holomorphic maps
F
g:= �
hol.maps X
e
−R
Σg X∗(ω)
In this way the path-integral for genus- worldsheet implies the counting of the holomorphic maps from the worldsheets to the Calabi-Yau
g
In general it is very hard to compute such a function mathematically. . . Fortunately, for a wide class of non-compact CY, we can compute these partition function exactly by utilizing string dualities !!
So, in the following, we focus on the dual pictures of the topological strings.
2. Conifold and Geometric Transition
- Deformed Conifold
We can deform the conifold by introducing the (complex structure) deformation
� ∈ R
Let us regard it as a fibration. Base is
R × T
2z = xy
xy = uv + �
{ |x|
|y|
|u| |v|
|x| = |y| = �
|z|
|u| = |v| = �
|z − �|
z = uv + �
|x|
|y|
|u| |v|
Re(z)
Fiber is and phases
R × T
2R = Im(z) T
2u → e
iβu, v → e
−iβv x → e
iαx, y → e
−iαy
z = xy
{
These cycles collapse on the locus or
z = 0 z = �
z = uv + �
z = 0
z = � α
β
{
z = 0
z = � S
3|x| = |y| = |z|
|u| = |v| = |z − �|
Im(z) = 0
z = xy
z = uv + �
x = ¯ y
u = ¯ v
1/2
1/2
By substituting it into the definition eq., we get the form of the minimal line
xy = uv + �
at the locus|x|
2+ |y|
2= � . . . S
3We choose a point of the non- compact fiber direction :
R × T
2fiber
{
- Resolved Conifold
z = 0
z = �
At , the 3-sphere vanishes, and we recover the conifold
� = 0
xy = uv
We can smooth the singular conifold by the resolution
S
2= P
1t
- Geometric Transition
we can define closed topological string on it
[Witten, ’93]
S
3we can wrap topological 3- branes on S3
gauge theory on the branes is the Chern-Simons theory on S3
open string theory
we will find open/closed duality duality between them !
- A-model topological string on resolved conifold [Gopakumar-Vafa, ’98]
F (g
s, t) = �
d≥1
1 d
�
2 sin dg
s2
�
−2e
−dtBy using this formula, we obtain
� 1
2 sin z2�2 = − 1
z2 + �
g=1
(−1)g−1B2g
2g(2g − 2)! z2g−2 1
ez − 1 = 1
z − 1
2 + �
g=1
(−1)g−1B2g
(2g)! z2g−1
F = − 1 gs2
�
d=1
e−dt
d3 − 1
12 log(1 − e−t) + �
g=2
gs2g−2 (−1)g−1B2g 2g(2g − 2)!
�
d=1
e−dt d3−2g
- large-N duality as gauge/gravity duality
amplitudes of gauge theory
‘tHooft’s idea
closed string genus expansion
!?
Let us study SU(N) Chern-Simons theory as the gauge theory [Witten, `88]:
F = log Z
gauge= �
g
g
s2g−2F
g(λ) = log Z
string= �
g,h
g
s2g−2λ
2g−2+hF
g,hλ = N g
sZ
CS(S
3) = 1
(k + N)
N/2N −1
�
j=1
2 sin
N −jjπ
k + N
Z
CS(S
3) = 1
(k + N)
N/2N −1
�
j=1
2 sin
N −jjπ k + N
g
s= 2π k + N
t = iλ = 2πiN k + N
F = log Z
CS= − N
2 log(k + N) +
�
N j=1(N − j) log(2 sin jπ
k + N )
= − N
2 log(k + N) −
�
N j=1(N − j) log( 2πj
k + N )
+
�
N j=1(N − j)
�
∞ n=1log(1 − g
s2j
24π
2n
2)
By using the formula sin(πz) = πz
�∞ n=1
(1 − z2 n2 )
F
non-pertF
pert:
:
F
pertF
pert=
N −1
�
j=1
(N − j)
�
∞ n=1�
∞ k=11 k
1
n
2kj
2k� g
s24π
2�
kζ(2k)
=
�∞ k=1
ζ(2k) k
� gs2 4π2
�k N −1�
j=1
(N − j)j2k
�
j=1
jk = Nk 2 +
[k2]
�
g=0
k+1C2g Nk+1−2g B2g k + 1
+
�
k g=12k
C
2g−2N
2k+2−2gB
2g2g
N2k+2 B0
(2k + 1)(2k + 2) power-sum formula
N
F
pertF
pert=
N −1
�
j=1
(N − j)
�
∞ n=1�
∞ k=11 k
1
n
2kj
2k� g
s24π
2�
kζ(2k)
=
�∞ k=1
ζ(2k) k
� gs2 4π2
�k N −1�
j=1
(N − j)j2k
+
�
k g=12k
C
2g−2N
2k+2−2gB
2g2g
N2k+2 B0
(2k + 1)(2k + 2)
λ = N g
sF
pert= g
s−2(· · · ) + g
s0(· · · )
+ �
g=2
�
k=1
g
s2g−2λ
2k+2−2gζ(2k) k
B
2g(2π)
2k 2kC
2g−2`tHooft expansion !!
F
(g≥2)= �
g=2
g
s2g−2F
g(λ)
F
g(≥2)(λ) = B
2g�
h=0
λ
2hζ(2g + 2h − 2) (2π)
2g+2h−22g+2h−2
C
2g−2g(2g + 2h − 2)
2g+2h−3
C
2hg(2g − 2)
�
n=1
1
(2πn)
2g+2h−2+
�
∞ g=2g
s2g−2B
2g2g(2g − 2)
B
2g−2(2g − 2)!
constant maps
F
g (≥2)= B
2g2g(2g − 2)
�
∞ n=1�
∞ h=02 λ
2h 2g+2h−2C
2h1
(2πn)
2g+2h−2= B
2g2g(2g − 2)
�
∞ n=1� 1
(2πn + λ)
2g−2+ 1
(2πn − λ)
2g−2�
= B
2g2g(2g − 2)
�
∞ n∈Z�=01
(2πn + λ)
2g−2F
non-pert= · · · + �
g≥2
g
s2g−2B
2g2g(2g − 2)
1
(λ)
2g−2non-pert. part gives the n=0 part
binomial theorem
+
�
∞ g=2g
s2g−2B
2g2g(2g − 2)
�
n∈Z
1
(2πn + λ)
2g−2F = ( g
s−2, g
s0-terms ) + �
g=2
g
s2g−2B
2g2g(2g − 2)
B
2g−2(2g − 2)!
�
g=2
g
s2g−2B
2g2g(2g − 2)
(−1)
g(2g − 3)!
�
∞ d=1d
2g−3e
−dtThis is precisely the world sheet instanton corrections for A- model on resolved conifold !!
�
n∈Z
1
n + z = 2πi
�
∞ d=0e
−2πidzt = iλ
S
3geometric transition
closed topological string on resolved conifold
open topological string on deformed conifold
=
In this way, we find out that the Chern-Simons partition function is equal to the topological string amplitude for the resolved conifold.
Worldsheet formulation of topological strings Conifold and geometric transition
Plan of the lecture
・ Geometric engineering of gauge theories
・ Application to AGT relation
Part 1
Part 2
Revision of Part 1
F (g
s, t) = �
g≥0
�
β∈H2(X,Z)
�
d≥1
n
gβ1 d
�
2 sin dg
s2
�
2g−2e
−d�β,t�S
3geometric transition
closed topological string on resolved conifold
open topological string on deformed conifold
=
3. Geometric Engineering of Gauge Theory
In the following, we focus on string theory on toric CY (generalization of conifold)
toric Calabi-Yau : Local models of Calabi-Yau manifolds
(describe the structure in neighborhood of singurarity) Geometric engineering
AdS/CFT . . .
ADE singularity
ADE gauge symmetry
fibration over
R(|z|) C
S
1(θ) z = |z|e
iθ :- complex plane
t
CP
1- resolved conifold
- Symplectic quotient
toric date s.t.
moment map
: Calabi-Yau condition
� v
i∈ Z
3Q
ai∈ Z
µ
a(z) =
N +3
�
j=1
Q
aj|z
j|
2z
j→ e
i Pa Qjaαaz
jM = C
N +3//G
= ∩
Na=1µ
−1a(t
a)/G
�
j
Q
ja= 0
G = U (1)
NN +3
�
i=1
Q
ai� v
i= 0
a = 1, · · · , N
- Symplectic quotient
Y K
Y K
Y K
toric date
Calabi-Yau condition
toric diagram
web diagram
dual graph
- resolved conifold
Q
i= +1, +1, −1, −1
� v
1=
1 0 0
�v
2=
1 1 0
�v
3=
1 0 1
�v
4=
1 1 1
µ = �
µi ∈ Z≥0 | µ1 ≥ µ2 ≥ · · ·� - topological vertex formalism
2. Assign Young diagrams for each edges of these parts
1. Decompose a toric web-diagram into vertices and propagators
3. Glue them to get topological string partition function
How to compute topological string amplitudes for toric Calabi-Yau manifolds ?
Locally they look like a conifold Geometric transition enable us to
calculate these amplitudes using Chern- Simons theory
Topological vertex [AMKV, ‘03]
Decomposition of toric web-diagram Parts
: trivalent vertex . . . local patch
: edes . . . 1.
2.
CP
1C
3ν
λ
µ
µ ν
vertex function
framing factor & propagator
f
µ(q)
n(−1)
|µ|e
−t|µ|δµ, ν
tC
λ,µ,ν(g
s)
Gluing along a leg is done by the following procedure
vertex function propagator framing factro
�
ν
C
λµν(−1)
|ν|e
−t|ν|(f
ν)
nC
λ�µ�νtZ = · · · · · ·
ν ν
tλ
µ
�µ
λ
�t
C
λµν(q) = q
κµ /2s
νt(q
−ρ) �
η
s
λt/η(q
−ν−ρ)s
µ/η(q
−νt−ρ)
S
λ(x
1, x
2, · · · , x
N) = det(x
iλj+N −j) det(x
iN −j)
s
µ(x)s
ν(x) = �
λ
c
λµ,νs
λ(x)
s
λ/µ(x) = �
λ
c
λµ,νs
ν(x)
Schur function
skew Schur function
q
−ρq
−µ−ρx
i= q
−µi+i− 12x
i= q
i− 12i = 1, 2, 3, · · ·
κ
µ= �
i
µ
i(µ
i+ 1 − 2i)
Q = e
−tq = e
−gsGluing rule
C
λµν(q) = q
κµ /2s
νt(q
−ρ) �
η
s
λt/η(q
−ν−ρ)s
µ/η(q
−νt−ρ)
vertex funstion
{
Z = · · · �
ν
C
λµν(−Q)
|ν|(f
ν)
nC
λ�µ�νT· · ·
- A-model topological string on resolved conifold [Gopakumar-Vafa, ’98]
F = �
d
1 d
Q
d(q
d/2− q
−d/2)
2= �
n
− log(1 − Qq
n)
nZ = �
n=1
(1 − Qq
n)
nF (g
s, t) = �
d≥1
1 d
�
2 sin dg
s2
�
−2e
−dtQ = e
−tq = e
−gs−
- topological vertex for the resolved conifold
Z = �
ν
C
φφν(−Q)
|ν|C
φφνt= �
ν
s
ν(q
−ρ)(−Q)
|ν|s
νt(q
−ρ)
�
µ
s
µt(x)s
µ(y) = �
i,j
(1 + x
iy
j)
s
µ(Qx) = Q
|µ|s
µ(x)
=
�
∞ n=1(1 − Qq
n)
n{
t ν
C
ΦΦνC
ΦΦνT- Large-N computation of the glueball superpotential
Type IIA theory with N D6-branes wrappiing on 3-sphere inside the deformed conifold
IR
SU(N) super Yang-Mills theory ... glueballN = 1
effective glueball superpotential is given by the open topological string
W (S) = N �
h
h S
h−1F
g=0,h= N F
g=0�(S)
[BCOV, ’94]
S = TrWαW α
F
0(S) = 1
2 S
2log S + �
h=2
B
2h−2(2h − 2)(2h)! S
2hW (S) = N S log S + · · ·
= − �
n∈Z
(S + 2πin) log(S + 2πin)
NVeneziano-Yankielowcz superpotential
infinitely many domain walls
generalization Dijkgraaf-Vafa theory
- geometric engineering
A singularity CY 3-fold1
S
2small
3-form field
C
µνλmassless U(1) gauge field
A
3µbrane on
D2
D2 ¯
brane onW
µ+W
µ−}
Let us consider compactification of Type IIA on the CY.
SU(2) Yang-Mills field !
Type IIA on
ADE singularity
N=2 4D ADE gauge theory
Topological A-model on [BCOV, ’94]
S
eff=
�
d
4x ∂
ti∂
tjF
0(t) F
i∧ F
j+ �
d
4x �
g=1
F
g(t) (T
2)
g−1R
2U(1) gauge field strength in N=2 SUGRA multiplet LEEA takes the following form
F
g is the topological string free energy !�T � ∼ �
� ∼ g
s- Seiberg-Witten theory
Low energy effective action of gauge theory is described by Seiberg- Witten prepotential N = 2
�Φ� = diag(a
1, · · · , a
N)
Low energy effective theory is Higgsed by vevSU (N ) → U(1)N −1
are Cartan gauge fields
S
eff=
�
τ
ijF
µνiF
jµνd
4x + · · ·
τ
ij= ∂
2∂a
i∂a
jF(a, Λ)
F
µνii = 1, · · · , N − 1 U (1)
N −1- Nekrasov formulae [Nekrasov, ‘02]
Nekrasov gave the generating function of Seiberg-Witten prepotential via instanton caluculus
Z
Nek.(a, Λ, �) = exp
�
∞ g=0�
2g−2F
g(a, Λ)
F
0(a, Λ) = F
SW(a, Λ)
The higher genus terms correspond to the corrections from the N=2 supergravity background fields (graviphotons)
Topological BRST symmetry Q reduces the “path integral” to usual integral.
the local minima of the action dominate the integral
�F �
2instanton
F + �F = 0
In the presence of the gravitational background, the N=2 theory becomes a topological field theory
Z =
�
DA · · · e
− g21 {Q,V }The localization formula reduces these Nekrasov partition functions to combinatrical expression (without integration)
Z = �
Y1,··· ,YN
q
| �Y |z
vector(�a, �
1,2; � Y )z
matters(�a, m, �
1,2; � Y )
z
vector(�a, �
1,2; � Y )
=
�
N a,b=1�
(i,j)∈Ya
(a
a− a
b− �
1(Y
bjT− i + 1) + �
2(Y
ai− j + 1))
−1× �
(i,j)∈Yb
(aa − ab + �1(Ybi − j + 1) − �2(YajT − i + 1))−1
�
1= −�
2= �
We will focus on the case of
Example : local Hirzebruch surface
K → P
1× P
1This geometry is a fibration of singularity over base . The SU(2) gauge symmetry emerges from the string theory on the singularity.
A
1P
1Y
1Y
2P
1baseP
1fiberZ = �
µ1,µ2,µ3,µ4
Q
F |µ1|+|µ3|Q
B|µ2|+|µ4|q
−κµ1 /2 +κµ2 /2 −κµ3 /2 −κµ4 /2× C
φ µ1 µ4tC
φ µ2t µ1tC
µ2 φ µ3C
φ µ4 µ3t= �
µ2,µ4
Q
B|µ2|+|µ4|q
+κµ2 /2 −κµ4 /2K
µ4 µ2(Q
F) K
µ2t µ4t(Q
F)
N=2 SU(2) gauge theory
K
Y1,Y2(Q) = S
Y T1
(q
−ρ)S
Y2(q
−ρ) �
W
Q
|W |S
W(q
−Y1−ρ)S
W(q
−Y2T −ρ)
� �
W
Q|W |SW (q−ρ)SW (q−ρ)
= S
Y T1
(q
−ρ)S
Y2(q
−ρ)
�
∞ i,j=11 − Qq
i+j−11 − Qq
−Y1i−Y2 jT +i+j−1SY1(q−ρ) = q�Y T� �
t∈Y
(1 − qhY (t))−1 where
Q
B= (βΛ)
4F F
F
F
F
Q
F= e
−4βaq = e
−2β�R
4× S
1βThis is precisely the Nekrasov partition function of the N=2 SU(2) pure SYM on
We can recover the 4-dimensional result by taking
β → 0
λ λ µ
µ
ν ν
C
3 -patch melting crystal cornergrand-canonical ensemble melting
crystals topological vertex !
- Duality to Crystal melting [Okounkov-Leshetikin-Vafa, ‘04]
Z
λ,µ,ν= �
crystals
e
−gs#(boxes)C
λ,µ,ν(g
s)
1
k
BT = g
s4. AGT conjecture
B Liouville (q) = Z Nekrasov (q)
[Alday-Gaiotto-Tachikawa, ‘09]
“AGT relation” : The equivalence between a Nekrasov instanton partition function of 4D gauge theory and the conformal block of 2D Liouville CFT on the associated Rieman surface
SU(2) quiver gauge theory
pants decomposition
conformal block on the surface
Free-field CFT vs U(1)-theory
Let us consider the free CFT with the background charge Q
�
�
4 i=1e
αiφ(zi)� = �
i<j
(z
i− z
j)
−αiαj�φ(z
1)φ(z
2)� = − ln(z
i− z
j)
z
1,··· ,4= 0, q, 1, ∞
B
free CFT= (1 − q)
−α2α3m
1m
2We choose
(1 − q)
−m1m2= �
Y
q
|Y |�
(i,j)∈Y
�
f =1,2
φ(m
f, (i, j)) E(0, Y, (i, j))
2Some algebra leads to the following expansion
φ(m, (i, j)) = m + i − j
E(a, Y, (i, j)) = a + (Y
jT− i + 1) + (Y
i− j)
�
Y
χ
Y(x)χ
Y(y) = exp �
n
nx
ny
nwhere we use
( )
This is the Nekrasov partition function for the “U(1) gauge theory with 2-flavors”!
B
free CFT= Z U (1),N
f=2
- “Derivation” of AGT conjecture [Dijkgraaf-Vafa, `09]
Recall the geometric transition of A-model topological string
N A-branes
Mirror B-model topological string of the setup is
N B-branes
S
2S
3S
3closed A-model geometry corresponding to SU(2) gauge theory with 4-flavors is
open B-model on B-branes on
S
2m
1m
2m
3m
4mirror symmetry
&
geometric transition
N
1N2
N
3N
4m
i= g
sN
iopen B-model = matrix model
N B-branes insertion of [Dijkgraaf-Vafa, `02]
V
N= det(Φ − Λ)
N�
�
4 i=1V
Ni� =
�
N ×N
dΦ
�
4 i=1det(Φ − Λ
i)
Ni=
�
dNz �
I<J
(zI − zJ)2 �
i,I
det(zI − Λi)Ni
Coulomb-gas expression of the conformal block !!
: Dotsenko-Fateev integral
The geometric transition provides a “proof” of the mysterious AGT relation.
・ formulation of topological strings
・ geometric transition
Summary
・ Applications of geometric transition
AGT relation
glueball superpotential
Nekrasov partition function