Post-Doctoral Research Visit F/M Distributed Voronoi diagrams for large-scale optimal transport

Contract type : Fixed-term contract

Renewable contract : Yes

Level of qualifications required : PhD or equivalent

Other valued qualifications : Doctor degree (Ph.D.)

Fonction : Post-Doctoral Research Visit

Level of experience : Recently graduated

About the research centre or Inria department

The Inria Saclay-Île-de-France Research Centre was established in 2008. It has developed as part of the Saclay site in partnership with Paris-Saclay University and with the Institut Polytechnique de Paris .

The centre has 39 project teams , 27 of which operate jointly with Paris-Saclay University and the Institut Polytechnique de Paris; Its activities occupy over 600 people, scientists and research and innovation support staff, including 44 different nationalities.


Within the framework of the COSMOGRAM project, in the PARAM project-team

  • The COSMOGRAM project, currently funded by an Inria exploratory action (AeX grant)
  • COSMOGRAM aims at developping new geometric methods for computational cosmology


Partitipation to one international conference per year is foreseen for this post 

travel expenses are covered within the limits of the scale in force.


Assignments :
With the help of Bruno Lévy, the recruited person will be taken to develop a novel algorithm to compute large-scale Voronoi diagrams on PC clusters.

For a better knowledge of the proposed research subject :

Collaboration :
The recruited person will work in close collaboration with Bruno Lévy, in Nancy, and will work in collaboration with the other members of the PARMA team in Orsay (mainly Quentin Mérigot and Hugo Leclerc)

Responsibilities :
The person recruited is responsible for developping and implementing a new algorithm for computed gigantic generalized Voronoi diagrams on a PC cluster. An abstract theoretical algorithm is described in:

  • Transform the abstract algorithm into a practical algorithm, that can be effectively implemented on a PC cluster
  • Implement and conduct practical experiments using the Grid5000 infrastructure, computing large scale Voronoi diagrams
  • Connect it to the existing semi-discrete optimal transport code, conduct large-scale optimal-transport computations
  • Possible project extension (2nd year): beyond the L2 cost, propose algorithms for partial optimal transport (intersection between Laguerre diagram and spheres), and Laguerre cells with more complicated shapes. Explore generalizations in higher dimensions.

Main activities

Main activities (5 maximum) :

  • Algorithmic design
  • Mathematical analysis
  • Implementation in C++ / MPI
  • Experimentation with Grid5000

Additional activities (3 maximum) :


  • Redaction of scientific articles (targets: Journal of Computational Physics, Physical Review, ACM Trans on Graphics)
  • Presentation at conferences (target: Supercomputing)


Technical skills and level required : Ph.D in computer science

Languages : English

Relational skills : Ability to work in a research group, and to interact with researchers of other fields (mathematicians, physicists)

Other valued appreciated : curiosity, sense of humour

Benefits package

  • Subsidized meals
  • Partial reimbursement of public transport costs
  • Leave: 7 weeks of annual leave + 10 extra days off due to RTT (statutory reduction in working hours) + possibility of exceptional leave (sick children, moving home, etc.)
  • Possibility of teleworking (after 6 months of employment) and flexible organization of working hours
  • Professional equipment available (videoconferencing, loan of computer equipment, etc.)
  • Social, cultural and sports events and activities
  • Access to vocational training
  • Social security coverage


Monthly gross salary : 2.788 euros