On Integrability of Type 0A Matrix Model in the Presence of D brane

TL;DR

This paper studies the integrability of the type 0A matrix model with a spacelike D brane, revealing a necessary constraint that aligns the model with string theory and results in a finite partition function with integrable structure.

Contribution

It introduces a specific operator constraint in the matrix model that ensures consistency with string theory and demonstrates the integrable Toda hierarchy structure of the partition function.

Findings

Constrained matrix model matches string theory predictions.

Partition function becomes finite and corresponds to a deformed Fermi surface.

Partition function exhibits integrable Toda hierarchy structure.

Abstract

We consider type 0A matrix model in the presence of a spacelike D brane,localized in matter direction at any arbitrary point. It appears that in order to have an appropriate string/MQM correspondence we must need to impose a constraint on the matrix model side which is equivalent to an operator constraint on the matter part of the boundary state that arises from open string boundary condition. This condition constrains the Hilbert space generated by the macroscopic loop operator but the bulk matrix model remains unaffected, thereby describing a situation parallel to string theory. We have analyzed the constrained theory with uncompactified as well as compactified time and have shown that it is in good agreement with string theory. Without this constraint, the grand canonical partition function for MQM on a circle in the presence of the brane diverges while the constrained partition function is finite and corresponds to that of a deformed Fermi surface, as expected within the compactified theory. Matrix model path integral on a circle in the presence of the brane is expressed as Fredholm determinant. We consider matrix model in the presence of the brane, to be perturbed by momentum modes. We obtain the expression of MQM wave function in this background from collective field theory analysis. We have shown with the help of this constraint that the grand canonical partition function has an integrable structure and can be expressed as tau function of Toda hierarchy. Finally we have analyzed the dispersionless limit.