activity
20242026
collaborators

8 papers

hep-th2026

Carroll Geometry Meets De Sitter Space via Holography

Chris D. A. Blair, Niels A. Obers, Ziqi Yan

We explain how to relate the ideas of Carroll geometry, matrix theory on instantonic objects, and infinite boost limits of M-theory. Based on these new insights, we explore the imp…

hep-th2025

Quantum carrollian bosonic strings

José Figueroa-O'Farrill, Emil Have, Niels A. Obers

We study a recently discovered carrollian bosonic string, described classically by a sigma model where both the worldsheet and the target spacetime are carrollian. After fixing the…

hep-th2025

Hydrodynamics without Boost-Invariance from Kinetic Theory: From Perfect Fluids to Active Flocks

Kevin T. Grosvenor, Niels A. Obers, Subodh P. Patil

We derive the hydrodynamic equations of perfect fluids without boost invariance [1] from kinetic theory. Our approach is to follow the standard derivation of the Vlasov hierarchy b…

hep-th2025

Dual Non-Lorentzian Backgrounds for Matrix Theories

Chris D. A. Blair, Johannes Lahnsteiner, Niels A. Obers +1

We study properties of non-Lorentzian geometries arising from BPS decoupling limits of string theory that are central to matrix theory and the AdS/CFT correspondence. We focus on d…

hep-th2025

Gravitational solitons and non-relativistic string theory

Troels Harmark, Johannes Lahnsteiner, Niels A. Obers

We explore the non-relativistic string theory (NRST) limit of type II string theory and its action on gravitational solitons. As a start, we exhibit in detail that the NRST limit i…

hep-th2025

Matrix Theory Reloaded: A BPS Road to Holography

Chris D. A. Blair, Johannes Lahnsteiner, Niels A. Obers +1

We revisit the decoupling limits that lead to matrix theories on D-branes. We highlight the BPS nature of these limits, in which the target space geometry becomes non-Lorentzian an…