DISCnet Students Profiles

Andrius Tamosiunas - 2017 Entry

University of Portsmouth, ICG

Testing Models of Modified Gravity


About Andrius

I did my MPhys degree at the University of Edinburgh where my research projects were focused on early universe cosmology, or, more concretely, cosmic inflation. After finishing my undergraduate master’s degree, I spend two years working in the airline industry, where I was responsible for airline pricing and software development using techniques from data science and machine learning. Exploring these computational techniques led me to consider pursuing a PhD in cosmology, which would allow me to combine my theoretical knowledge of the subject gained in the undergraduate studies with the newly acquired practical knowledge in data science. Nowadays, I am studying a variety of models of gravity with an emphasis on testing them using cosmological probes such as galaxy clusters, numerical methods and simulations.

What is your research?

Modifying the currently best-accepted theory of gravity – the theory of general relativity – offers an alternative way of solving some of the most important problems in cosmology. In particular, the problems of the accelerated expansion of the universe and dark matter could be possibly tackled by considering modifications to the known laws of gravity. There is a wide variety of modified gravity models, with different predictions and properties. The challenge is to find ways of testing these models and to compare their predictions with those from general theory of relativity. This can be done by using different cosmological probes, such as weak lensing and X-ray signals from galaxy clusters, large scale structure, cluster abundances and the CMB.  In addition, the predictions of various modified gravity models can be studied and tested by employing computer simulations. My research is currently focused on using X-ray and weak lensing measurements of galaxy clusters to constrain models of modified gravity, including chameleon and emergent gravity.

There is a wide variety of modified gravity models, with different predictions and properties. 

What have you done in the first 6 months?

My work in the last 6 months was mostly focused on testing the model of entropic (emergent) gravity using the weak lensing and X-ray data from galaxy clusters. Currently the results are being prepared to be published in a journal. In addition, I have presented my results in the Britgrav 2018 conference.


Also recently I have been offered a funded DISCnet summer project at the African Institute for Mathematical Sciences in South Africa, where I will be working with Cape Town public transport data and will have a chance to apply the experience gained in data intensive training.

Supervisory Team

Bob Nichol, David Bacon, and Kazuya Koyama 


Keep up with Andrius's research on his university profile and LinkedIn.