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Instantons in Lifshitz Field Theories Developments in String Theory and Quantum Field Theory @ YITP, Nov. 12th, 2015 arXiv:1507.06456 (JHEP 1510 (2015) 021) Toshiaki Fujimori, Muneto Nitta (Keio Univ.) Toshiaki Fujimori
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Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Jul 10, 2022

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Page 1: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz Field Theories

Developments in String Theory and Quantum Field Theory @ YITP, Nov. 12th, 2015

arXiv:1507.06456 (JHEP 1510 (2015) 021)Toshiaki Fujimori, Muneto Nitta (Keio Univ.)

Toshiaki Fujimori

Page 2: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

Instanton

4d gauge theory 2d non-linear σ model

common properties

Page 3: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

Lifshitz-type field theories

t ! �zt, x ! �x

: no Lorentz symmetry

⇠ 1

E2 � p2z

weighted power counting

z > 1

Page 4: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

Examples of Lifshitz field theories

[ Horava, 2008 ]

[ Kanazawa-Yamamoto, 2014 ]

[ Das-Murthy, 2009 ]

[ Anagnostopoulos et al, 2010 ]CPN

O(N)

[ Horava, 2009 ]

z = d

Page 5: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

Examples of Lifshitz field theories

[ Horava, 2008 ]

[ Kanazawa-Yamamoto, 2014 ]

[ Das-Murthy, 2009 ]

[ Anagnostopoulos et al, 2010 ]CPN

O(N)

instantons in Lifshitz-type sigma model and gauge theory

z = d

Page 6: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

supersymmetry in Lifshitz-type models

Q ! ei✓2Q,

: Weyl spinors under SO(2) spatial rotation

Q ! e�i ✓2 Q,

{Q, Q} = 2i@t

in 2+1-dimensions

Page 7: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

supersymmetry in Lifshitz-type models

Q ! ei✓2Q, Q ! e�i ✓

2 Q,

{Q, Q} = 2i@t

in 2+1-dimensions

: Weyl spinors under SO(2) spatial rotation

Page 8: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

superfield formalism

only time derivative

Page 9: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

supermultiplets

real scalar + Dirac fermion + real auxiliary field

Page 10: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

action for real multiplets

time derivative spatial derivative

Page 11: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

action for real multiplets

time derivative spatial derivative

spatial derivative

Page 12: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

bosonic part of action

W (t) =

Zd

2xW(�, @i�, · · · )

“detailed balance condition”

[ P. Horava, “Membranes at Quantum Criticality,” (2009) ]

Page 13: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

2d theory

bosonic part of action

W (t) =

Zd

2xW(�, @i�, · · · )

[ P. Horava, “Membranes at Quantum Criticality,” (2009) ]

⟨0|O|0⟩⟨0|0⟩ =

∫DφOe−2W

∫Dφ e−2W

Page 14: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

BPS bound and BPS equation

BPS eq. = gradient flow for W

Page 15: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

an explicit example of W

⇡3(G) = Z

instanton number

W (t) = α

∫d2xTr

[(iU †∂iU)(iU †∂iU)

]

Page 16: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

W for 3d Lifshitz sigma model

⇡3(G) = Z

Wess-Zumino-Witten term

instanton number

W (t) = α

∫d2xTr

[(iU †∂iU)(iU †∂iU)

]

Page 17: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

bosonic part ca supersymmetric Lifshitz model

t ! �

2t, xi ! �xi

S = ⇠

Zdtd

2x ✏

ijkTr⇥(U †

@iU)(U †@jU)(U †

@kU)⇤

⇡3(G) = Z topological charge (Skyrmion)

∝ nξ

O(∂2t ) O(∂4

x)

z=2 Lifshitz scaling invariance

Page 18: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

det

✓@x

0i

@xj

◆= 1

xi ! x

0i,

simplified case

BPS equation = gradient flow

iU †∂tU = α∂i(iU†∂iU) + ξ[U †∂1U,U

†∂2U ]

iU †∂tU = ξ[U †∂1U,U†∂2U ]

Page 19: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

det

✓@x

0i

@xj

◆= 1

xi ! x

0i,

BPS equation = gradient flow

iU †∂tU = α∂i(iU†∂iU) + ξ[U †∂1U,U

†∂2U ]

iU †∂tU = ξ[U †∂1U,U†∂2U ]

simplified case

Page 20: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

reduced BPS equation

symmetric ansatz for instanton

G = SU(2)

U(1) ⊂

(t, ρ ≡ x21 + x2

2)

Page 21: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

numerical solution

(t, ρ ≡ x21 + x2

2)

Page 22: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

exact solution S1 ⇥ R2

φ = exp

(−2πn

ρ+ it

β

)

GA

U(1) ⊂

U(1) ⊂

Ssol = 8π2nξ

Page 23: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

W for gauge theories

W =

R2n−1

CS2n−1

Chern-Simons term

S ≥∫

R2n

Tr [F ∧ · · · ∧ F ]

Page 24: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

dimensionless : renormalizable

(5+1)d Lifshitz-Yang-Mills theory

S =1

g

2

Zdtd

5xTr

⇥F

20i + (✏ijklmFjkFlm)2

t ! �3t, xi ! �xi,z=3 Lifshitz scaling

anisotropic Weyl transf. dt2 + (dxi)2 → λ(t, x)6dt2 + λ(t, x)2(dxi)2

Page 25: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

(5+1)d Lifshitz-Yang-Mills theory

F0i =1

4✏ijklmFjkFlm

dCS5

symmetric ansatz

S =1

g2

Z

R6

Tr(F ^ F ^ F )

SO(5) ⊂

Page 26: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

symmetric ansatz

Ftρ = − 1

9ρ2(|φ|2 − 1)2 Dtφ = i(|φ|2 − 1)Dρφ

[Witten, 1977]

Ftρ = − 1

ρ2(|φ|2 − 1) Dtφ = iDρφ

(t, ρ ≡ |xi|3)

Page 27: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

4d and 6d instantons (action density)

SO(2) ∈ SL(2,R)

isotropic anisotropic

Page 28: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

future works

⟨0|O|0⟩⟨0|0⟩ =

∫DφOe−2W

∫Dφ e−2W

Page 29: Toshiaki Fujimori - yukawa.kyoto-u.ac.jp

Instantons in Lifshitz field theory

known example: 2d NLSM (non-Lifshtiz)

(@t

+ i@x

)�i = 0 instantons in NLSM

Kahler form