3 papers
astro-ph.CO2024
Cosmic topology. Part I. Limits on orientable Euclidean manifolds from circle searches
Pip Petersen, Yashar Akrami, Craig J. Copi +9
The Einstein field equations of general relativity constrain the local curvature at every point in spacetime, but say nothing about the global topology of the Universe. Cosmic micr…
astro-ph.CO2024
Cosmic topology. Part IVa. Classification of manifolds using machine learning: a case study with small toroidal universes
Andrius Tamosiunas, Fernando Cornet-Gomez, Yashar Akrami +16
Non-trivial spatial topology of the Universe may give rise to potentially measurable signatures in the cosmic microwave background. We explore different machine learning approaches…
astro-ph.CO2024
Cosmic topology. Part IIa. Eigenmodes, correlation matrices, and detectability of orientable Euclidean manifolds
Johannes R. Eskilt, Yashar Akrami, Stefano Anselmi +11
If the Universe has non-trivial spatial topology, observables depend on both the parameters of the spatial manifold and the position and orientation of the observer. In infinite Eu…