Prof. Jun Nishimura of KEK Theory Center and his collaborators performed numerical simulation of string theory with supersymmetric deformation, and calculated various physical quantities that probe the emergent spacetime. The simulation also provided a clear understanding to the puzzle that the original theory is not retrieved in the limit of the deformation parameter going to zero. The research results were published in Physical Review Letters on November 24, 2025 (US Eastern Time).
https://journals.aps.org/prl/abstract/10.1103/y1rm-n85b

String theory is a promising candidate for quantum gravity, in which even spacetime can fluctuate quantum mechanically. In particular, it is widely believed that the fundamental degrees of freedom in string theory is actually a bunch of huge matrices, from which spacetime and all kinds of particles emerge dynamically. In such a matrix model formulation of string theory, a crucial question is what kind of spacetime emerges from matrices. Recently this issue was addressed in string theory with supersymmetric deformation, and a particular spacetime geometry was identified in a certain range of the deformation parameter. In this paper, a careful numerical simulation was performed for this deformed matrix model, and various quantities that probe the emergent spacetime were calculated. Moreover, the simulation clarified why the original model is not retrieved in the limit of the deformation parameter going to zero.

It turned out that a new minimum of the potential appears in the deformed model, while the matrix configuration that gives the potential minimum goes to infinity in that limit and hence becomes invisible in the original model. This provides an interesting example in which a tiny deformation of a theory can lead to totally different consequences, which is expected to have a great impact also in broad areas of theoretical physics.
This research is based on collaboration with Chien-Yu Chou and Cheng-Tsung Wang, students majoring in particle and nuclear physics at SOKENDAI.