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Large N instantons from topological strings
by Marcos Mariño, Ramon Miravitllas
Submission summary
Authors (as registered SciPost users):  Marcos Mariño · Ramon Miravitllas 
Submission information  

Preprint Link:  scipost_202403_00027v1 (pdf) 
Date submitted:  20240319 13:36 
Submitted by:  Miravitllas, Ramon 
Submitted to:  SciPost Physics 
Ontological classification  

Academic field:  Physics 
Specialties: 

Approach:  Theoretical 
Abstract
The $1/N$ expansion of matrix models is asymptotic, and it requires nonperturbative corrections due to large $N$ instantons. Explicit expressions for large $N$ instanton amplitudes are known in the case of Hermitian matrix models with one cut, but not in the multicut case. We show that the recent exact results on topological string instanton amplitudes provide the nonperturbative contributions of large $N$ instantons in generic multicut, Hermitian matrix models. We present a detailed test in the case of the cubic matrix model by considering the asymptotics of its $1/N$ expansion, which we obtain at relatively high genus for a generic twocut background. These results can be extended to certain nonconventional matrix models which admit a topological string theory description. As an application, we determine the large $N$ instanton corrections for the free energy of ABJM theory on the threesphere, which correspond to Dbrane instanton corrections in superstring theory. We also illustrate the applications of topological string instantons in a more mathematical setting by considering orbifold GromovWitten invariants. By focusing on the example of $\mathbb{C}^3/\mathbb{Z}_3$, we show that they grow doublyfactorially with the genus and we obtain and test explicit asymptotic formulae for them.
Current status:
Reports on this Submission
Strengths
Numerical tests of nonperturbative correction for various matrix models are very nontrivial.
Report
The nonperturbative correction of matrix models is an important subject. The authors use results from topological string instanton amplitudes to study these corrections for generic, multicut, hermitian matrix models. Following previous works, the paper proposes an explicit form and tests it carefully for twocut solutions of a cubic matrix model. The numerical agreement is very impressive. They also test for ABJM theory, whose nonperturbative correction is interpreted as D2instantons in previous works. It is interesting to establish a closed form of nonperturbative correction for matrix models from topological string instanton amplitudes.
Relating to the results in this paper, for the ABJM theory, nonperturbative correction for the matrix model was also studied in Fermi gas formalism initiated by one of the authors. There, another expansion for D2instantons was known and the final result on nonperturbative corrections was also given by topological string theory. The relation to the present work is not very clear to me. Do the result from Fermi gas and the current proposal relate to each other in a symplectic transformation? The expansion in Fermi gas formalism seems to work only for ABJMlike theories, but the proposal in the present paper seems more general. I would suggest to provide some comments on the relations, if the authors have some in mind.
Namely, I think that the results of the manuscript is very impressive and I recommend the manuscript for publication after adding some comments.
Requested changes
Comments on the relation to previous results in Fermi gas formalism.
Recommendation
Ask for minor revision
Report 1 by Minxin Huang on 2024428 (Invited Report)
Strengths
1. Nonperturbative formulation is probably the most outstanding problem in string/Mtheory. Nonperturbative effects are also important in many topics in mathematics and physics, in particular in situations involving strong coupling dynamics. The author’s approach is a promising direction where many concrete precise results can be obtained.
2. The numerical tests have some quite impressive precision.
3. These examples establish the universality of the general formalism proposed in the previous papers.
Weaknesses
1. The main novelty of general formalism has been proposed in the previous papers. The current manuscript is just an application to more though still nontrivial examples.
2. The current tests are mostly numerical. It would be better have some analytic derivation or proof of some of the results.
Report
The authors apply the results in the previous recent papers [22, 23] to some more nontrivial examples. In the previous papers, in the context of topological string theory on CalabiYau 3folds, some novel conjectures were proposed concerning the relation between the instanton action and the periods of CalabiYau geometry, as well as the formulas for nonperturbative transseries free energy. The manuscript summarized the developments in Section 2, e.g. formulas (2.4), (2.9), then test the formula (2.9) in three more examples related to matrix models using the large order asymptotics of the perturbative free energy. Such tests often involve some heroic efforts of computations to very large order.
As in the previous papers, the manuscript provides some impressive numerical tests. As can be seen in the various figures, the dots extracted from the large order asymptotics lie well on the lines from the proposed transseries formula, providing convincing evidence for its validity. We should note that the computations of perturbative free energy are by themselves quite nontrivial, as one needs to use various boundary conditions to fix the holomorphic ambiguity. But a surprising aspect in [22, 23] is that once the perturbative part is determined, the boundary conditions for transseries parts are relatively quite simple. Using previous works on the holomorphic anomaly equation for the transseries parts, simple formulas at least for low orders can be written, as e.g. in (2.9).
I think the manuscript contains some solid research results. I recommend publication of the manuscript.
Recommendation
Publish (easily meets expectations and criteria for this Journal; among top 50%)