Research

I am part of the group on Complex Networks Dynamics and Control (Social Networks).

The aim of my work is to study a collective decision-making process in a community of agents exchanging opinions, characterized by the coexistence of collaborative and antagonistic interactions. In particular, this process is described by a nonlinear interconnected dynamical model (whose equilibrium points encode the decisions) with sigmoidal nonlinearities and signed interaction graph representing the community of agents. The purpose is to investigate the existence and stability of the equilibria of the system and how the presence of antagonism between the agents affects the dynamical behavior of the community, using tools of nonlinear dynamics (bifurcation theory) and theory of signed networks.

Publications

PhD Thesis

1. A. Fontan, Collective decision-making on networked systems in presence of antagonistic interactions, Linköping Studies in Science and Technology. Dissertations, No. 2166, 2021. [DiVA]

Journal papers

1. A. Fontan and C. Altafini, The role of frustration in collective decision-making dynamical processes on multiagent signed networks, IEEE Transactions on Automatic Control, to appear, 2022.
   DOI: 10.1109/TAC.2021.3123222
2. A. Fontan and C. Altafini, A signed network perspective on the government formation process in parliamentary democracies, Scientific Reports, vol. 11 (5134), 2021.
   DOI: 10.1038/s41598-021-84147-3
3. A. Fontan, G. Shi, X. Hu and C. Altafini, Interval Consensus for Multiagent Networks, IEEE Transactions on Automatic Control, vol. 65 (5), pp. 1855-1869, 2019.
   DOI: 10.1109/TAC.2019.2924131.
4. A. Fontan and C. Altafini, Multiequilibria Analysis for a Class of Collective Decision-Making Networked Systems, IEEE Transactions on Control of Network Systems, vol. 5 (4), pp. 1931-1940, 2018.
   DOI: 10.1109/TCNS.2017.2774014.

Conference papers

1. A. Fontan and C. Altafini, On the properties of Laplacian pseudoinverses, 60th IEEE Conference on Decision and Control (CDC), Austin, Texas, USA, December 2021.
   
2. A. Fontan and C. Altafini, Describing government formation processes through collective multiagent dynamics on signed networks (extended abstract), 1st Virtual IFAC World Congress, July 2020.
   
3. A. Fontan and C. Altafini, Achieving a decision in antagonistic multiagent networks: frustration determined commitment strength, 57th IEEE Conference on Decision and Control (CDC), Miami Beach, FL, USA, December 2018.
   DOI: 10.1109/CDC.2018.8619615.
4. A. Fontan and C. Altafini, Investigating mixed-sign equilibria for nonlinear collective decision-making systems, 56th IEEE Conference on Decision and Control (CDC), Melbourne, Australia, December 2017.
   DOI: 10.1109/CDC.2017.8263755.
5. A. Fontan, G. Shi, X. Hu and C. Altafini, Interval Consensus: a novel class of constrained consensus problems for multiagent networks, 56th IEEE Conference on Decision and Control (CDC), Melbourne, Australia, December 2017.
   DOI: 10.1109/CDC.2017.8264270.

Other

• Certificate of Outstanding Service as Reviewer for the year 2019.