Welcome to my (always tidy but frequently outdated) virtual home!
I'm Georgios (which is the greek-analog of George but I mostly go for giorgos or yorgos), and I am a postdoc researcher interested in algorithmic problems (mainly, with social choice motivation).

[Apr, 2024] Excited to share—just joined the group of Piotr Skowron for a postdoc (funded by his ERC Starting Grant for the project PRO-DEMOCRATIC)!                   👉 new website location

[Mar, 2024] Stepping stone moment: defended my PhD thesis, eager for what's to come!

[Feb, 2024] Will you be in New Zealand soon, exploring its nature, Maori culture, or attending AAMAS? If so, let's chat. I'll be there presenting our work (with Georgios Amanatidis, Aris Filos-Ratsikas, Philip Lazos and Evangelos Markakis) on the power of proxy voting for elections with incomplete votes.

[Nov, 2023] Starting my short-term internship with IOG's research team!

[Oct, 2023] Appreciated the time spent visiting Piotr Skowron in Warsaw, looking forward to a return, and hoping for sunnier days.

[Oct, 2023] Grateful for the recognition with the "Call to Arms Award" as an ECAI'23 reviewer!

[Aug, 2023] Celebrating our win in the IJCAI'23 Computational Social Choice Competition (with Roy Fairstein and Bin Sun)! Here are our winning moments: [1],[2].

[Apr, 2023] My summer just got even more exciting! I'm grateful to have been accepted and granted to attend the Summer School on Computational Social Choice in Amsterdam in mid-July. There, my favorite poster will accompany me.

[Apr, 2023] Yay! Our paper with Markus Brill, Vangelis Markakis and Jannik Peters, on proportionality guarantees for elections with interdependent issues, made it to IJCAI'23! See you in Macao! UPD: And guess what? You'll also find a poster showcasing our work at the COMSOC workshop!

[Jul, 2022] Our paper with Vangelis Markakis and Artem Tsikiridis, on truthful mechanisms with bounded approximation guarantees for a covering problem motivated by spatial models in crowdsourcing markets, has been accepted for publication at SAGT'22!

[Jun, 2022] For the following two months, I will participate in the Summer Internship Program of Archimedes: a newly established unit of Athena Research Center for basic research on AI, Data Science and Algorithms.

[May, 2022] Hooray! Not only the remaining of my PhD studies will be supported with a fellowship by H.F.R.I., but also my proposal was ranked 1st among the applications submitted in the scientific area of Mathematics and Information Sciences! :)

[Apr, 2022] I had a (short but wonderful) research visit at LAMSADE of Université Paris-Dauphine and the CNRS, hosted by Jérôme Lang and funded by COST Action (gamenet).

[Jul, 2021] Our paper (with Vangelis Markakis) on the computational aspects of a novel Liquid Democracy framework for expressing approval based preferences has been accepted for publication at SAGT'21!

[May, 2021] If you have ever wondered about the role of the treewidth parameter in elections under Conditional Minisum Approval Voting rule, or if you are the type of person that would be interested in controlling the outcome of such an election, you have to check our paper (with Vangelis Markakis) which has been accepted for publication at IJCAI'21 and for presentation at COMSOC'21 workshop!

[Apr, 2021] Will you, in the 9th of April, have 5 minutes to talk about the winner determination problem for elections under Conditional Approval Voting rule? If yes, join the Rump Session of COMSOC Video Seminar! UPD: Did you miss it? Martin, Gary, Kyle, Homer, Bart, Maggie and I, appear right after the 4th minute of this recording.

[Oct, 2020] You do see that direct and representative democracy have both pros and cons and you are interested in (the CS aspects of) a voting procedure that lies somewhere in between? Here is our presentation on Liquid Democracy for the md4sg group on Civic Participation.

[May, 2020] If the "Complexity of Conditional Minisum Approval Voting Rule" sounds interesting to you or if you and your friends are struggling expressing your true preferences when trying to decide on a common meal, you should check our paper (with Vangelis Markakis) (or the corresponding presentation or poster) which has been accepted for publication at IJCAI'20! UPD: We have detected an error in Lemma 2 which affects the claimed approximation ratio in Theorem 1. The corrected version can be found here.





If both your intentions are good and the weather in Warsaw is not dreadful, you can reach me at

University of Warsaw
Faculty of Mathematics, Informatics and Mechanics
str. Banacha 2, 02-097 Warsaw
Room: 5020.

Otherwise, e-mail me at

gpapasotiropoulos[at]gmail[dot]com
(consider resending if you don't receive an answer for 3 days).