Observational and Numerical Cosmology Research Group

(Group supervisor: Professor Manolis Plionis)

Basic aim of Numerical Cosmology is the development of Cosmological N-body codes that can simulate not only the large-scale structure of the Universe and smaller non-linear structures but also phenomena that are dominated by baryonic physics. Through the comparison with the observable Universe (Observational Cosmology), the validity of cosmological models or gravity theories (Theoretical Cosmology) is checked, and our knowledge of the origin and nature of the observable universe could be promoted. Furthermore, simulations can also study specific small-scale phenomena in the direction of improving methods of astronomical observation, the calibration of stellar evolution theories etc.
Tools of the trade of NC are the N-body simulations, where dynamical systems of many particles under the influence of forces (in cosmological scales usually only gravity is considered) are evolved. The research orientation of the group is the development of simple codes for cosmological simulations and the development of software for the analysis of N-body simulation data. Examples of topics developed so far are:

(i) code for direct N-body simulations and their graphical representation
(ii) Friends-of-Friends and Minimum Spanning Tree algorithms for the analysis of Dark Matter (DM) Halo distributions from cosmological simulations
(iii) code for the study of galaxy alignments around DM halos and/or galaxy clusters.

 cosmo


Extract of the DEUS FUR simulation centered on a certain dark matter halo.


Maria Chira (MSc student) (group coordinator) 
maria
 I was born in 1992 in Athens, but in 1996 I moved to Arta where I come from. I have been living in Thessaloniki since 2010, where I study. I hold a degree from the Physics Department and I am currently a post-graduate student of the Aristotle University of Thessaloniki. I am interested in research in the fields of Computational Cosmology. Specifically, my under-graduate thesis was on A Percolation (Friends-of-Friends) Algorithm Development and its application to Cosmological N-body simulations After completing my postgraduate Studies in Computational Physics my goal is to continue my academic studies with a relevant PhD.
Ziampras Alexandros (BSc student)
alex
I was born in 1995 and since then live in Thessaloniki, where I study Physics in AUTh. My research interests mainly involve Astrophysics and Cosmology, and generally anything that can be approached with a computer. I'm currently a member of this research team and I am working on a bachelor thesis on N-body simulations and their graphical representation. After obtaining my degree, I'm planning to enroll in a Master's programme on Astrophysics.
Vasiliki Paraschaki (BSc student)
vicky

I was born in Thessaloniki and I am currently studying Physics in A.U.TH. as a undergraduate student. My two huge loves are Space and cats (first astronaut cat in the works!). Currently I am pleasantly struggling with Cosmology and more specific with my undergraduate thesis with subject the alignment of elliptical galaxies inside and in the outskirts of galaxy clusters.

Graduated Students
Konstantinos Kovlakas (MSc 2016)  
kostas
Graduate of the MSc program: "Numerical Physics" at the AUTH (2016). MSc Thesis supervisor: Manolis Plionis. MSc thesis:
"An MST library and GUI: Application to Cosmological Simulations".
Publication:
Kovlakas, Plionis & Corasaniti (2016), in preparation.
Currently a PhD student with full scholarship at the University of Crete.
Maria Manolopoulou (MSc 2014) 
kostas
Graduate of the MSc program: "Numerical Physics" at the AUTH (2014). MSc Thesis supervisor: Manolis Plionis. MSc thesis:
"Galaxy Cluster's Rotation".
Publication:
Manolopoulou & Plionis (2016), MNRAS in press.
Currently a PhD student with full scholarship at the University of Edinburgh.
Kostas Migkas (BSc 2015) 

Graduate of the Physics Bsc program at the AUTH (2015). Bsc Thesis
"Constraining Cosmological Parameters and Testing the Isotropy of the Hubble Expansion using Supernovae Ia"
Thesis supervisor: Manolis Plionis. Publication:
Migkas & Plionis 2016, "Testing the Isotropy of the Hubble Expansion", RMXAA, 52, 132
Currently an Astrophysics MSc student with full scholarship at the University of Bonn.
Eutuxia Madika (BSc 2015) 
kostas
Graduate of the Physics Bsc program at the AUTH (2015). Bsc thesis:
"The Luminosity Function of different galaxy types in A1656"
Thesis supervisor: Manolis Plionis. Publication based on the thesis is currently being written.
Currently an Astrophysics MSc student at the University of Bonn.
Alexandros Papastergiou (BSc 2015) 
kostas
Graduate of the Physics Bsc program at the AUTH (2015). Bsc thesis:
"The Cluster M/L and the Ωm parameter".
Thesis supervisor: Manolis Plionis.
Currently an MSc student in Computer Science at the Univ. of Nottingham.
Aristidis Amvrosiadis (BSc 2014) 

Graduate of the Physics Bsc program at the AUTH (2014). Bsc thesis:
"The 2-p correlation function of DM halos in Light-Cone Cosmological Simulations".
Thesis supervisor: Manolis Plionis.
Currently an Astrophysics PhD student at the Univ. of Cardiff.
Nikos Samaras (BSc 2014) 

Graduate of the Mathematics Bsc program at the AUTH (2014). Bsc thesis:
"Solutions of Freedman's equations with and without Cosmological Constant".
Thesis supervisor: Manolis Plionis.
Currently an Theoretical Phsyics MSc student at the Univ. of Paris.
Katerina Dima (BSc 2014) 

Graduate of the Physics Bsc program at the AUTH (2014). Bsc thesis:
"Evolution of Perturbations in an Expanding Space and Tests of the Linear Approximation usiN-Body Cosmological Simulations".
Thesis supervisor: Manolis Plionis.
Currently an Astrophsyics MSc student at the Univ. of Athens