Download presentation
Presentation is loading. Please wait.
Published byJonah Warren Modified over 8 years ago
1
1 1 A lattice formulation of 4 dimensional N=2 supersymmetric Yang-Mills theories Tomohisa Takimi (TIFR) Ref) Tomohisa Takimi arXiv:1205.7038 [hep-lat] 19 th July 2012 Free Meson Seminar
2
2 1. Introduction Supersymmetric gauge theory One solution of hierarchy problem of SM. Dark Matter, AdS/CFT correspondence Important issue for particle physics 2 *Dynamical SUSY breaking. *Study of AdS/CFT Non-perturbative study is important
3
3 Lattice: Lattice: A non-perturbative method lattice construction of SUSY field theory is difficult. Fine-tuning problemSUSY breaking Difficult * taking continuum limit * numerical study
4
4 Lattice: Lattice: A non-perturbative method lattice construction of SUSY field theory is difficult. Fine-tuning problemSUSY breaking Difficult * taking continuum limit * numerical study
5
5 Lattice: Lattice: A non-perturbative method lattice construction of SUSY field theory is difficult. Fine-tuning problemSUSY breaking Difficult * taking continuum limit * numerical study
6
6 Lattice: Lattice: A non-perturbative method lattice construction of SUSY field theory is difficult. Fine-tuning problemSUSY breaking Difficult * taking continuum limit * numerical study
7
7 Fine-tuning problem Difficult to perform numerical analysis Time for computation becomes huge. To take the desired continuum limit. SUSY breaking in the UV region Many SUSY breaking counter terms appear; is required. prevents the restoration of the symmetry Fine-tuning of the too many parameters. (To suppress the breaking term effects) Whole symmetry must be recovered at the limit
8
8 Example). N=1 SUSY with matter fields gaugino mass,scalar massfermion mass scalar quartic coupling Computation time grows as the power of the number of the relevant parameters By standard lattice action. (Plaquette gauge action + Wilson fermion action) too many4 parameters
9
Lattice formulations free from fine-tuning 9 {,Q}=P _ P Q A lattice model of Extended SUSY preserving a partial SUSY O.K
10
Lattice formulations free from fine-tuning 10 We call as BRST charge Q A lattice model of Extended SUSY preserving a partial SUSY : does not include the translation O.K
11
11 Picking up “BRS” charge from SUSY Redefine the Lorentz algebra by a diagonal subgroup of the Lorentz and the R-symmetry in the extended SUSY ex. d=2, N=2 d=4, N=4 There are some scalar supercharges under this diagonal subgroup. If we pick up the charges, they become nilpotent supersymmetry generator which do not include infinitesimal translation in their algebra. (E.Witten, Commun. Math. Phys. 117 (1988) 353, N.Marcus, Nucl. Phys. B431 (1994) 3-77
12
12 Does the BRST strategy work to solve the fine-tuning ?
13
(1) Let us check the 2-dimensional case Let us consider the local operators Mass dimensions Quantum corrections of the operators are :bosonic fields :fermionic fields :derivatives :Some mass parameters
14
(1) Let us check the 2-dimensional case Let us consider the local operators Mass dimensions Quantum corrections of the operators are :bosonic fields :fermionic fields :derivatives :Some mass parameters Mass dimensions 2!Super-renormalizable Relevant or marginal operators show up only at 1-loop level.
15
(1) Let us check the 2-dimensional case Let us consider the local operators Mass dimensions Quantum corrections of the operators are :bosonic fields :fermionic fields :derivatives :Some mass parameters Mass dimensions 2!Super-renormalizable Relevant or marginal operators show up only at 1-loop level. Irrelevant
16
(1) Let us check the 2-dimensional case Let us consider the local operators Mass dimensions :bosonic fields :fermionic fields :derivatives :Some mass parameters Mass dimensions 2!Super-renormalizable Relevant or marginal operators show up only at 1-loop level. Only these are relevant operators
17
Only following operator is relevant: Relevant No fermionic partner, prohibited by the SUSY on the lattice At all order of perturbation, the absence of the SUSY breaking quantum corrections are guaranteed, no fine-tuning.
18
18 Remaining Task (4 dimensional case)
19
19 (2) 4 dimensional case, If dimensionless ! All order correction can be relevant or marginal remaining at continuum limit. Operators with
20
20 (2) 4 dimensional case, If dimensionless ! All order correction can be relevant or marginal remaining at continuum limit. Prohibited by SUSY and the SU(2)R symmetry on the lattice.
21
21 (2) 4 dimensional case, If dimensionless ! All order correction can be relevant or marginal remaining at continuum limit. Marginal operators are not prohibited only by the SUSY on the lattice
22
22 Fine-tuning of 4 parameters are required. The formulation has not been useful..
23
23 The reason why the four dimensions have been out of reach. (1) UV divergences in four dimensions are too tough to be controlled only by little preserved SUSY on the lattice.
24
24 The reason why the four dimensions have been out of reach. (1) UV divergences in four dimensions are too tough to be controlled only by little preserved SUSY on the lattice. How should we manage ?
25
25 The reason why the four dimensions have been out of reach. (1) UV divergences in four dimensions are too tough to be controlled only by little preserved SUSY on the lattice. How should we manage ? Can we reduce the 4d system to the 2d system ?
26
26 4d to 2d treatment: (i) We separate the dimensions into several parts in anisotropic way. (ii) We take the continuum limit of only a part of the four directions. During this step, the theory is regarded as a lower dimensional theory, where the UV divergences are much milder than ones in four -dimensions.
27
27 (i) We separate the dimensions into several parts in anisotropic way. (ii) We take the continuum limit of only a part of the four directions. During this step, the theory is regarded as a lower dimensional theory, where the UV divergences are much milder than ones in four -dimensions. 4d to 2d treatment:
28
28 4d to 2d (i) We separate the dimensions into several parts in anisotropic way. (ii) We take the continuum limit of only a part of the four directions. During this step, the theory is regarded as a lower dimensional theory, where the UV divergences are much milder than ones in four -dimensions.
29
29 4d to 2d treatment (i) We separate the dimensions into several parts in anisotropic way. (ii) We take the continuum limit of only a part of the four directions. During this step, the theory is regarded as a lower dimensional theory, where the UV divergences are much milder than ones in four -dimensions.
30
30 (i) We separate the dimensions into several parts in anisotropic way. (ii) We take the continuum limit of only a part of the four directions. During this step, the theory is regarded as a lower dimensional theory, where the UV divergences are much milder than ones in four -dimensions. 4d to 2d treatment:
31
31 (i) We separate the dimensions into several parts in anisotropic way. (ii) We take the continuum limit of only a part of the four directions. During this step, the theory is regarded as a lower dimensional theory, where the UV divergences are much milder than ones in four -dimensions. 4d to 2d treatment:
32
32 (i) We separate the dimensions into several parts in anisotropic way. (ii) We take the continuum limit of only a part of the four directions. During this step, the theory is regarded as a lower dimensional theory, where the UV divergences are much milder than ones in four -dimensions. (1) Even little SUSY on the lattice can manage such mild divergences. (2)A part of broken symmetry can be restored by the first step, to be helpful to suppress the UV divergences in the remaining steps. 4d to 2d treatment:
33
33 (iii) Final step: taking the continuum limit of the remaining directions. Symmetries restored in the earlier steps help to suppress tough UV divergences in higher dimensions. 4d to 2d treatment:
34
34 The treatment with steps (i) ~ (iii) will not require fine-tunings. 4d to 2d treatment: (iii) Final step: taking the continuum limit of the remaining directions. Symmetries restored in the earlier steps help to suppress tough UV divergences in higher dimensions.
35
35 Non-perturbative formulation using anisotropy. Hanada-Matsuura-Sugino Prog.Theor.Phys. 126 (2012) 597-611 Nucl.Phys. B857 (2012) 335-361 Hanada JHEP 1011 (2010) 112 Supersymmetric regularized formulation on Two-dimensional lattice regularized directions.
36
36 Non-perturbative formulation using anisotropy. Hanada-Matsuura-Sugino Prog.Theor.Phys. 126 (2012) 597-611 Nucl.Phys. B857 (2012) 335-361 Hanada JHEP 1011 (2010) 112 Supersymmetric regularized formulation on (1) Taking continuum limit of Full SUSY is recovered in the UV region Theory on the
37
37 Non-perturbative formulation using anisotropy. Hanada-Matsuura-Sugino Prog.Theor.Phys. 126 (2012) 597-611 Nucl.Phys. B857 (2012) 335-361 Hanada JHEP 1011 (2010) 112 Supersymmetric regularized formulation on (1) Taking continuum limit of Full SUSY is recovered in the UV region Theory on the (2) Moyal plane limit or commutative limit of.
38
38 Non-perturbative formulation using anisotropy. Hanada-Matsuura-Sugino Prog.Theor.Phys. 126 (2012) 597-611 Nucl.Phys. B857 (2012) 335-361 Hanada JHEP 1011 (2010) 112 Supersymmetric regularized formulation on (1) Taking continuum limit of Full SUSY is recovered in the UV region Theory on the (2) Moyal plane limit or commutative limit of. Bothering UV divergences are suppressed by fully recovered SUSY in the step (1)
39
39 Non-perturbative formulation using anisotropy. Hanada-Matsuura-Sugino Prog.Theor.Phys. 126 (2012) 597-611 Nucl.Phys. B857 (2012) 335-361 Hanada JHEP 1011 (2010) 112 Supersymmetric regularized formulation on (1) Taking continuum limit of Full SUSY is recovered in the UV region Theory on the (2) Moyal plane limit or commutative limit of. Bothering UV divergences are suppressed by fully recovered SUSY in the step (1) No fine-tunings !!
40
40 Our work
41
41 We construct the analogous model toHanada-Matsuura-Sugino Advantages of our model: (1) Simpler and easier to put on a computer (2) It can be embedded to the matrix model easily. (Because we use “deconstruction”) Easy to utilize the numerical techniques developed in earlier works.
42
42 Moreover, we resolve the biggest disadvantage of the deconstruction approach of Kaplan et al. In the conventional approach, it is necessary to introduce SUSY breaking moduli fixing terms, SUSY on the lattice is eventually broken (in IR, still helps to protect from UV divergences)
43
43 Moreover, we resolve the biggest disadvantage of the deconstruction approach of Kaplan et al. We introduce a new moduli fixing term with preserving the SUSY on the lattice !! In the conventional approach, it is necessary to introduce SUSY breaking moduli fixing terms, SUSY on the lattice is eventually broken (in IR, still helps to protect from UV divergences)
44
44 Our Formulation
45
45 Schematic explanation
46
46 4 –dimensions are divided into
47
47 4 –dimensions are divided into
48
48 4 –dimensions are divided into
49
49 From this regularized space we want to take the continuum limit without any fine-tuning
50
From this regularized space we want to take the continuum limit without any fine-tuning as
51
51 The way to construct(schematic explanation)
52
52 (0) Starting from the Mass deformed 1 dimensional matrix model with 8SUSY (Analogous to BMN matrix model)
53
53 (0) Starting from the Mass deformed 1 dimensional matrix model with 8SUSY Performing Orbifolding
54
54 Performing deconstuction
55
55 Performing deconstuction Additional 1 dimension emerges
56
56 Performing deconstuction But this dimension is unstable, fluctuating, and it can crush
57
57 To stabilize the space, we introduce Moduli fixing term
58
58 To stabilize the space, we introduce Moduli fixing term Then the space would be stabilized
59
59 To stabilize the space, we introduce Moduli fixing term Then the space would be stabilized (I introduce the moduli fixing term without breaking SUSY on the lattice !)
60
60 (1) Then we obtain the orbifold lattice theory on
61
61 For the numerical study we need to regularize (1) Then we obtain the orbifold lattice theory on
62
62 We will take momentum cut-off regularization (1) Then we obtain the orbifold lattice theory on For the numerical study we need to regularize
63
63 We will take momentum cut-off regularization (1) Then we obtain the orbifold lattice theory on For the numerical study we need to regularize
64
(2)This is the hybrid regularized theory on 64
65
(2)This is the hybrid regularized theory on 65 This is still 2 dimensional theory. Additional 2 dimensions must be emerged.
66
(2)This is the hybrid regularized theory on 66 Taking Fuzzy Sphere solution.
67
(2)This is the hybrid regularized theory on Taking Fuzzy Sphere solution. 67
68
(3) Finally we obtain the non-perturbative formulation for the 4-d N=2 SYM on 68
69
69 How to take the continuum limit (schematic explanation)
70
70
71
71 We manage the momentum cut-off first !
72
72
73
73
74
74 Continuum limit of the orbifold lattice gauge theory.
77
Moyal plane limit
79
Until the limit We do not need Fine-tunings !!
80
But from
82
This limit is expected not smoothly connected..
83
83 Although our formulation might not be a formulation for the commutative gauge theory, It can be used for the non-commutative theories.
84
84 Detailed explanation
85
85 (0) Starting from the Mass deformed 1 dimensional matrix model with 8SUSY (Analogous to BMN matrix model) Orbifolding & deconstruction (1) Orbifold lattice gauge theory on 4 SUSY is kept on the lattice (UV) And moduli fixing terms will preserve 2 SUSY
86
86 Momentum cut off (2) Orbifold lattice gauge theory with momentum cut-off, (Hybrid regularization theory) Theory on Uplift to 4D by Fuzzy 2-sphere solution Actually all of SUSY are broken but “harmless” (3) Our non-perturbative formulation for 4D N=2 non-commutative SYM theories: Theory on
87
87 Detail of how to construct.
88
88 (0) Starting from the Mass deformed 1 dimensional matrix model with 8SUSY (Analogous to BMN matrix model) 88
89
89 (0) The Mass deformed 1 dimensional matrix model With mN × mN matrices and with 8-SUSY For later use, we will rewrite the model by complexified fields and decomposed spinor components.
90
90 We also pick up and focus on the specific 2 of 8 SUSY. By using these 2 supercharges and spnior decomposition and complexified fields, we can rewrite the matrix model action by “the BTFT form”
91
91 The transformation laws are
92
92 The important property of Globalgenerators :doublets :triplet If
93
93 The model hassymmetry with following charge assignment singlet Charge is unchanged under the
94
94 (1) Orbifold lattice gauge theory
95
95
96
96
97
(1) Orbifold lattice gauge theory Orbifold projection operator on fields with r-charge
98
98 (1) Orbifold lattice gauge theory Orbifold projection operator on fields with r-charge Orbifold projection: Discarding the mN ×mN components except the ones with mN ×mN indices
99
99 Example in N=3,
100
100 Example in N=3, From the gauge transformation law of the above under U(M) 3
101
101 Example in N=3, From the gauge transformation law of the above under U(M) 3
102
102 Example in N=3, From the gauge transformation law of the above under U(M) 3 Site Link
103
103 Under the projection, matrix model fields become lattice fields
104
SUSY on the orbifold lattice theory SUSY charges invariant under orbifold projection will be the SUSY on the lattice
105
105 SUSY on the orbifold lattice theory SUSY charges invariant under orbifold projection will be the SUSY on the lattice = # of site fermions # of SUSY on the lattice = # of SUSY with
106
106 SUSY on the orbifold lattice theory SUSY charges invariant under orbifold projection will be the SUSY on the lattice = # of site fermions # of SUSY on the lattice = # of SUSY with
107
107 SUSY on the orbifold lattice theory SUSY charges invariant under orbifold projection will be the SUSY on the lattice = # of site fermions # of SUSY on the lattice = # of SUSY with 4 fermions
108
108 SUSY on the orbifold lattice theory SUSY charges invariant under orbifold projection will be the SUSY on the lattice = # of site fermions # of SUSY on the lattice = # of fermions with 4 fermions 4SUSY is preserved on the lattice !!
109
109 I have explained Orbifolding 109
110
110 Next is Deconstruction
111
111 Next is Deconstruction 111
112
112 Deconstruction and continuum limit. *Orbifodling is just picking up the subsector of matrix model. (No space has appeared.) *No kinetic terms.
113
113 *Orbifodling is just picking up the subsector of matrix model. (No space has appeared.) *No kinetic terms. To provide the kinetic term and continuum limit, we expand the bosonic link fields around as Deconstruction and continuum limit.
114
114 Continuum limit. *By taking *If fluctuation around is small, We can obtain the mass deformed 2d SYM with 8SUSY at the continuum limit
115
115 Next we need to stabilize the lattice !! 115
116
116 To provide the proper continuum limit, the fluctuation must be small enough compared with. But in the SUSY gauge theory, there are flat directions which allows huge fluctuation. We need to suppress the fluctuation by adding the moduli fixing terms Moduli fixing terms. These break the SUSY on the lattice eventually. (Softly broken, so UV divergence will not be altered.)
117
117 Proposed new Moduli fixing terms with keeping SUSY We proposed a new moduli fixing terms without breaking SUSY !!
118
118 Proposed new Moduli fixing terms with keeping SUSY We proposed a new moduli fixing terms without breaking SUSY !! We utilized the fact 118 If
119
119 By a new moduli fixing term, the lattice becomes stabilized !!
120
120 Orbifold lattice action for 2d mass deformed SYM with moduli fixing terms is
121
121
122
122
123
123 (2) Momentum cut-off on the orbifold lattice theory.
124
124
125
125
126
126 To perform the numerical simulation, Remaining one continuum direction also must be regularized. We employ the momentum cut-off regularization in Hanada-Nishimura-Takeuchi Momentum cut-off is truncating the Fourier expansion in the finite-volume
127
127 Momentum cut-off in gauge theory To justify the momentum cut-off, we need to fix the gauge symmetry by the gauge fixing condition These condition fix the large gauge transformation which allows the momentum to go beyond the cut-off.
128
128 Momentum cut-off action on (Hybrid regularized theory) after gauge fixing.
129
129 And so on.. (Remaining parts are really boring, so I will omit the parts…)
130
130 Notes: (1) About the gauge fixing.
131
131 Notes: (1) About the gauge fixing. Gauge fixing does not spoil the quantum computation based on the gauge symmetry, because it is just putting the BRS exact term to the action, which does not affect the computation of gauge invariant quantity. Rather we should take this fixing as being required to justify the momentum cut-off to be well defined. Only for this purpose !!
132
132 Notes: (2) The cut-off might break the gauge symmetry, is it O.K ?
133
133 Notes: (2) The cut-off might break the gauge symmetry, is it O.K ? O.K !
134
134 Notes: (2) The cut-off might break the gauge symmetry, is it O.K ? O.K ! If the gauge symmetry is recovered only by taking, completely no problem. I would like to emphasize that what we are interested in is the theory at, not the theory with finite cut-off. There is no concern whether the regularized theory break the gauge sym. or not, since it is just a regularization.
135
135 Notes: (2) The cut-off might break the gauge symmetry, is it O.K ? O.K ! If the gauge symmetry is recovered only by taking, completely no problem. I would like to emphasize that what we are interested in is the theory at, not the theory with finite cut-off. There is no concern whether the regularized theory break the gauge sym. or not, since it is just a regularization. I will explain it later by including the quantum effects
136
136 (3) Uplifting to 4d by Fuzzy 2-sphere solution
137
137
138
138
139
139 Until here, the theory is still in the 2 dimensions. We need to uplift the theory to 4 dimensions. We will use the Fuzzy Sphere solutions!
140
140 Until here, the theory is still in the 2 dimensions. We need to uplift the theory to 4 dimensions. We will use the Fuzzy Sphere solutions! Derivative operators along fuzzy S2
141
141 We expand the fields in the fuzzy sphere basis which is spherical harmonics truncated at spin j:
142
142 We expand the fields in the fuzzy sphere basis which is spherical harmonics truncated at spin j: field on 2d
143
143 We expand the fields in the Fuzzy sphere basis which is spherical harmonics truncated at spin j: field on 2d Fuzzy S2 basis
144
144 We expand the fields in the Fuzzy sphere basis which is spherical harmonics truncated at spin j: field on 2d Fuzzy S2 basis Fuzzy S2 basis: (1) If we truncate the spherical harmonic expansion at spin j ⇒ Fuzzy S2 basis (2) 2j+1 ×2j+1 matrix (Tensor product is altered by Matrix product of 2j+1 ×2j+1 matrix ⇒ Total spin does not exceed j
145
We expand the fields in the Fuzzy sphere basis which is spherical harmonics truncated at spin j: field on 2d Fuzzy S2 basis field variable on target 4d space.
146
We expand the fields in the Fuzzy sphere basis which is spherical harmonics truncated at spin j: field on 2d Fuzzy S2 basis field variable on target 4d space. Fuzzy Sphere solution does not break 8 SUSY at all !!
147
147 By this uplifting, we have completed the construction of non-perturbative formulation for N=2 4d non- commutative SYM theories.
148
148 (ii) How to take the target continuum theory
149
149 In our formulation, 4-dimensions are divided into 3-parrts. Regularized by momentum cut-off sites parameters
150
150 In our formulation, 4-dimensions are divided into 3-parrts. Regularized by momentum cut-off sites parameters Task. Which direction should we deal with first ?
151
151 Criteria. In early lower dimensional stage, it is easier to handle the crude regularization breaking much symmetries.
152
152 Criteria. In early lower dimensional stage, it is easier to handle the crude regularization breaking much symmetries. We should undertake the crude regularization first !
153
153 Regularized by momentum cut-off sites parameters
154
154 Regularized by momentum cut-off sites parameters This one !!
155
155 Regularized by momentum cut-off sites parameters On the other hand, BPS state, SUSY is well protected.
156
156 Regularized by momentum cut-off sites parameters Then the order of taking the continuum limit is (1) (2) (3)
157
157 Then order of taking the limit becomes
158
158 (1) Momentum cut-off directions.
159
159 We manage the momentum cut-off first !
160
160
161
161 In finite the theory is one-dimensional theory. There is no UV divergences. There is no quantum correction breaking 2 SUSY and gauge symmetry. only by taking, orbifold lattice theory is recovered.
162
162 (2) Managing the orbifold lattice directions
163
163
165
165 Repeating the renormalization discussion in the early stage of this talk….
166
(1) Let us check the 2-dimensional case Let us consider the local operators Mass dimensions :bosonic fields :fermionic fields :derivatives :Some mass parameters Mass dimensions 2!Super-renormalizable Relevant or marginal operators show up only at 1-loop level. Only these are relevant operators
167
Only following operator is relevant: Relevant No fermionic partner, prohibited by the SUSY on the lattice At all order of perturbation, the absence of the SUSY breaking quantum corrections are guaranteed, no fine-tuning.
168
Only following operator is relevant: Relevant No fermionic partner, prohibited by the SUSY on the lattice At all order of perturbation, the absence of the SUSY breaking quantum corrections are guaranteed, no fine-tuning. In this step, the full 8 SUSY is restored !!
169
169 (3) Fuzzy S2 directions.
170
Moyal plane limit
172
172 In this step, since the full SUSY is preserved, we do not need to mind any quantum correction
173
173 In this step, since the full SUSY is preserved, we do not need to mind any quantum correction No fine-tuning !!
174
174 Notes: In the case of N=4 theory, we can continuously connect to the commutative theory in
175
175 Notes: On the other hand, N=2 theory, it is expected not to be continuously connectted to the commutative theory in Our theory is a non-perturbative formulation for the non- commutative gauge theory, but it is useful enough to investigate the non-perturbative aspects of gauge theories.
176
But from This limit is expected not smoothly connected..
177
177 Summary We provide a simple non-perturbative formulation for N=2 4-dimensional theories, which is easy to put on computer.
178
178 Moreover, we resolve the biggest disadvantage of the deconstruction approach of Kaplan et al. In the approach, to make the well defined lattice theory from the matrix model, we need to introduce SUSY breaking moduli fixing terms, SUSY on the lattice is eventually broken (in IR, still helps to protect from UV divergences)
179
179 Anisotropic treatment is useful for controlling the UV divergences.
180
180 End
181
181 Precise discussion
182
182 Only following diagrams can provide quantum corrections Bosonic tadpole with fermionic loop Bosonic 2-point function with fermionic loop Bosonic 2-point function with bosonic loop and derivative coupling
183
183 Only following diagrams can provide quantum corrections Bosonic tadpole with fermionic loop Bosonic 2-point function with fermionic loop Bosonic 2-point function with bosonic loop and derivative coupling
184
184 Momentum integration of the odd function Bosonic tadpole with fermionic loop Bosonic 2-point function with fermionic loop Bosonic 2-point function with bosonic loop and derivative coupling
185
185 Momentum integration of the odd function Bosonic tadpole with fermionic loop Bosonic 2-point function with fermionic loop Bosonic 2-point function with bosonic loop and derivative coupling = 0
186
186 Momentum integration of the odd function Bosonic tadpole with fermionic loop Bosonic 2-point function with fermionic loop Bosonic 2-point function with bosonic loop and derivative coupling = 0 No quantum correction !!
187
187
188
188 It becomes the theory on
189
189
190
190
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.