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hep-th2026

Quantum spacetime and quantum fluctuations in the IKKT model at weak coupling

Harold C. Steinacker

This paper aims to clarify conceptual aspects of emergent structure in IKKT-type matrix models. Even without any adjustable parameters in the action, non-trivial matrix vacua do ac…

hep-th2025

Spatially flat FLRW spacetimes with a Big Bang from matrix geometry

Christian Gaß, Harold Steinacker

We present an expanding, spatially flat () FLRW quantum spacetime with a Big Bang, considered as a background in Yang-Mills matrix models. The FLRW geometry emerges in the sem…

hep-th2025

One-loop effective action of the IKKT model for cosmological backgrounds

Emmanuele Battista, Harold C. Steinacker

We study cosmological solutions of the IKKT model with FLWR geometry, taking into account one-loop corrections. A previously discussed covariant quantum spacetime is found t…

hep-th2025

Minimal covariant quantum space-time

Alessandro Manta, Harold C. Steinacker

We discuss minimal covariant quantum space-time , which is defined through the minimal doubleton representation of . An elementary definition…

hep-th2024

Covariant cosmological quantum space-time, higher-spin and gravity in the IKKT matrix model

Marcus Sperling, Harold C. Steinacker

We discuss a -dimensional covariant quantum space-time describing a FLRW cosmology with Big Bounce, obtained by a projection of the fuzzy hyperboloid . This provide…

hep-th2024

-extended gravity from the IKKT matrix model

Alessandro Manta, Harold C. Steinacker, Tung Tran

We elaborate further on the one-loop effective action of the IKKT model on 3 + 1 dimensional covariant quantum spacetime in the presence of fuzzy extra dimensions. In particular, w…