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FRINATEK-Fri mat.,naturv.,tek

Unveiling the Nature of Gravity at Galaxy Clusters Scales

Alternative title: Tyngdekraftens natur avslørt av galaksehoper

Awarded: NOK 11.5 mill.

The nature of gravity is one of the great mysteries of physics. The aim of this proposal is to investigate whether there are alternative gravity models that describe the universe and its constituents better than general relativity. To achieve such a goal, we aim to confront predictions from several theoretical models of gravity theories beyond general relativity to astronomical measurements of galaxy cluster properties. Galaxy clusters are the most massive, gravity-bound structures in the universe, and their properties provide a sensitive probe for the nature of gravity. Current and near future galaxy studies by ESA and NASA will provide properties of clusters and galaxies to unparalleled details, which will allow us to understand how they were formed and how they are distributed in space and how they are grouped together. We perform computer simulations within the framework of several gravity theoretical models and compare the output data from these simulations with observations from satellite observations of galaxy studies.

I intend to run N-body and hydrodynamic cosmological simulations within General Relativity and theories beyond Einstein's gravity to obtain predictions of galaxy clusters properties and test them against data from spectrographic, x-ray and photometric galaxy surveys. The aim is to obtain 1) Novel and stricter constraints on the gravity theory at astrophysical and cosmological scales; 2) Semi-analytical models and simulations of astrophysical observables for Modified Gravity; 3) A list of promising astrophysical probes for modified gravity to be measured by galaxy surveys. In order to achieve these objectives I will 1) Perform hydro-n-body simulations in Modified Gravity and build semi-analytical models; 2) Investigate the degeneracies between baryonic physics and modified gravity; 3) Confront modify gravity predictions of baryonic observables with data from galaxy surveys; 4) Test the Equivalence Principle using environmental dependent astrophysical observables. This is a timeless project, since a new generation of galaxy surveys will measure the spatial distribution of millions of galaxies, offering an imminent opportunity to discover new physics: a new fundamental particle, a breakdown of General Relativity, or a hint on the nature of cosmic acceleration. This research will enable stronger cosmological constrains, increasing the power of future surveys and maximizing our potential to discover new physics from present and near future galaxy surveys. Without this research the scientific community will keep importing predictions and assumptions tested only within General Relativity to interpret and extract information from observations. The strengths of this new theoretical framework will be its flexibility, accuracy and speed. For instance, it will provide predictions for clustering statistics, down to scales much smaller than in state-of-the-art perturbation-theory-based models.

Funding scheme:

FRINATEK-Fri mat.,naturv.,tek