28 citations · 139 across the 16 of their papers we have counts for
17 papers
Cosmic topology. Part IIc. Detectability with non-standard primordial power spectrum
Joline Noltmann, Andrius Tamosiunas, Deyan P. Mihaylov +13
Non-trivial spatial topology of the Universe can imprint potentially observable signatures on the cosmic microwave background (CMB). In this study, we investigate how deviations fr…
Cosmic topology. Part IIb. Eigenmodes, correlation matrices, and detectability of non-orientable Euclidean manifolds
Craig J. Copi, Amirhossein Samandar, Glenn D. Starkman +13
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…
Cosmic topology. Part IIIb. Eigenmodes and correlation matrices of spin-2 perturbations in orientable Euclidean manifolds
Amirhossein Samandar, Javier Carrón Duque, Craig J. Copi +13
We study the eigenmodes of the spin-2 Laplacian in orientable Euclidean manifolds and their implications for the tensor-induced part of the cosmic microwave background (CMB) temper…
Interacting Dark Sector (ETHOS ): Cosmological Constraints from SPT Cluster Abundance with DES and HST Weak Lensing Data
A. Mazoun, S. Bocquet, J. J. Mohr +64
We use galaxy cluster abundance measurements from the South Pole Telescope (SPT) enhanced by Multi-Component Matched Filter (MCMF) confirmation and complemented with mass informati…
Cosmic topology. Part Ic. Limits on lens spaces from circle searches
Samanta Saha, Craig J. Copi, Glenn D. Starkman +11
Cosmic microwave background (CMB) temperature and polarization observations indicate that in the best-fit Cold Dark Matter model of the Universe, the local geometry is consiste…
Cosmic topology. Part IIIa. Microwave background parity violation without parity-violating microphysics
Amirhossein Samandar, Javier Carrón Duque, Craig J. Copi +11
The standard cosmological model, which assumes statistical isotropy and parity invariance, predicts the absence of correlations between even-parity and odd-parity observables of th…
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…
Using machine learning to optimise chameleon fifth force experiments
Chad Briddon, Clare Burrage, Adam Moss +1
The chameleon is a theorised scalar field that couples to matter and possess a screening mechanism, which weakens observational constraints from experiments performed in regions of…
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…
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…
Promise of Future Searches for Cosmic Topology
Yashar Akrami, Stefano Anselmi, Craig J. Copi +12
The shortest distance around the Universe through us is unlikely to be much larger than the horizon diameter if microwave background anomalies are due to cosmic topology. We show t…
Chameleon Screening in Cosmic Voids
Andrius Tamosiunas, Chad Briddon, Clare Burrage +3
A key goal in cosmology in the upcoming decade will be to form a better understanding of the accelerated expansion of the Universe. Upcoming surveys, such as the Vera C. Rubin Obse…
SELCIE: A tool for investigating the chameleon field of arbitrary sources
Chad Briddon, Clare Burrage, Adam Moss +1
The chameleon model is a modified gravity theory that introduces an additional scalar field that couples to matter through a conformal coupling. This `chameleon field' possesses a…
Chameleon Screening Depends on the Shape and Structure of NFW Halos
Andrius Tamosiunas, Chad Briddon, Clare Burrage +2
Chameleon gravity is an example of a model that gives rise to interesting phenomenology on cosmological scales while simultaneously possessing a screening mechanism, allowing it to…
Testing and Emulating Modified Gravity on Cosmological Scales
Andrius Tamosiunas
This thesis introduces a set of methods for testing models of modified gravity using galaxy clusters. In particular, a technique for constraining models with a chameleon screening…
Investigating Cosmological GAN Emulators Using Latent Space Interpolation
Andrius Tamosiunas, Hans A. Winther, Kazuya Koyama +3
Generative adversarial networks (GANs) have been recently applied as a novel emulation technique for large scale structure simulations. Recent results show that GANs can be used as…
Testing Emergent Gravity on Galaxy Cluster Scales
Andrius Tamosiunas, David Bacon, Kazuya Koyama +1
Verlinde's theory of Emergent Gravity (EG) describes gravity as an emergent phenomenon rather than a fundamental force. Applying this reasoning in de Sitter space leads to gravity…