About the project

MEETINGS:

1. Dec 15, 2017: B3DCMB kick-off @ APC:

Participants: D. Beck (APC), N. Chopin (CREST), J. Errard (APC), J. Grain (IAS), L. Grigori (INRIA), M. Le Jeune (APC), J. Papež, (INRIA), M. Tristram (LAL), R. Stompor (APC), C. Verges (APC)

Agenda:

• • R. Stompor: project overview + overview of the CMB DA pipeline + context – 1h;
  • D. Beck: numerical/statistical challenges in ML lensing potential and delensing estimators -20 mins
  • M. Tristram: numerical/statistlcal challenges in power spectrum estimators (ML, sampling) – 20 mins
  • J. Grain: numerical challenges in apodization optimisation for pure pseudo-spectrum methods – 20 mins
  • J.Errard: numerical/statistical challenges in component separation – 20 mins
  • N. Chopin: overview of likelihood approximation techniques – 30 mins
  • L.Grigori: recent progress in large-scale linear system solvers – 20 mins
  • J. Papež: messenger-field and PCG solvers. 20 mins
  • All: Concluding discussion/action items/next meeting – 1h.

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2. Feb 15, 2018: Collaboration meeting @ INRIA-Paris:

Participants: D. Beck (APC), N. Chopin (CREST), J. Errard (APC), J. Grain (IAS), L. Grigori (INRIA), M. Le Jeune (APC), J. Papež, (INRIA), D. Poletti (SISSA), O. Tissot (INRIA), M. Tristram (LAL), R. Stompor (APC), C. Vergès (APC)

Discussion topics:

• • New CG algorithms  including hands-on session on using the relevant software. (Olivier)
  • The map-making problem: is it solved yet ?!  (Davide)
  • Variational approximations (Nicolas)
  • Wiener Filtering in the lensing context from operational point of view (Dominic)
  • Apodization optimization from the operational point of view (Julien/Matt)
  • Defining the work plan for the ‘infrastructure” (Radek).

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3. May 17, 2018: WP#2 (statistical methods) meeting @ CREST

Participants: D. Beck (APC), N. Chopin (ENSAE), T. Cimic (INRIA), H. El Bouhargani (APC), J. Errard (APC), J. Papež, (INRIA), D. Poletti (SISSA), R. Stompor (APC), O. Tissot (INRIA), M. Tristram (LAL), C. Vergès (APC)

Discussion topics:

• Role of sampling techniques in CMB data analysis (Radek);
• Overview of new trends in Bayesian approximation techniques (Nicolas);
• Population MC (Dominic);
• Hamiltonian MC (Hamza, Clara);
• Gibbs (Davide);
• Metropolis-Hastings (Matt);
• Nested sampling (Josquin).

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4. Informal, ad-hoc meeting @ INRIA: Nov 15, 2018: (WP#3)

Participants: T. Cimic (INRIA), H. El Bouhargani (APC), L. Grigori (INRIA), A. Jamal (APC) , J. Papež (INRIA), R. Stompor (APC), O. Tissot (INRIA)

Discussion topics:

1. T. Cimic (INRIA): First results/experiences from applying Enlarged CG to the CMB map-making problem.
2. J. Papež, O. Tissot  (INRIA): Solving sequences of linear systems in the component separation context.
3. Discussion and planning.

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5. Informal meeting at INRIA, (WP#3), Dec 7, 2018

Participants: T. Cimic (INRIA), G. Ducroucq (CREST/ENSAE), H. El Bouhargani (APC), A. Jamal (APC), J. Papež (INRIA), R. Stompor (APC), O. Tissot (INRIA)

Discussion topics:

1. Map-making background and solutions (Radek);
2. Progress on implementation of the map-making code using MIDAPACK (Hamza).

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6. February 21, 2019, kick-off of the second year of the project.

We met at INRIA.

Participants: D. Beck (APC), N. Chopin (CREST/ENSAE), T. Cimic (INRIA), G. Ducroucq (CREST/ENSAE), H. El Bouhargani (APC), J. Errard (APC), J. Grain (IAS), L. Grigori (INRIA), A. Jamal (APC), J. Papež (INRIA), R. Stompor (APC), M. Tristram (LAL), C. Vergès (APC)

Discussion topics:

1. Project status and meeting goals (Radek);
2. Approximate Bayesian Computations for CMB (Gabriel);
3. Novel CG techniques for CMB map-making (Thibault);
4. Solving sequences of linear system for CMB component separation (Jan);
5. Performance test of FFTW for CMB applications (Aygul);
6. Massively parallel CMB map-making code development status (Hamza);
7. Using S4CMB software package for quick, realistic simulations (Clara).
8. Summary, concluding remarks and plans for the future (Radek).

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7. April 18, 2019, WG#2 working meeting @ ENSAE/CREST.

Partcipants: N. Chopin (CREST/ENSAE), G. Ducrocq (CREST/ENSAE), J. Errard (APC), R. Stompor (APC)

Discussion topic: 

Approximate Bayesian Computation applied to cosmological parameter estimation from CMB data.

9. June 17, 2021, kick-off of the fourth (and last!) year of the project.

The meeting was held remotely via ZOOM.

Participants: N. Chopin (CREST/ENSAE), T. Cimic (INRIA), G. Ducroucq (CREST/ENSAE), H. El Bouhargani (APC), J. Errard (APC),  L. Grigori (INRIA), M. Morshead (APC), A. Rizzieri (APC),  R. Stompor (APC), M. Tristram (LAL),

Discussion topics:

1. Project status and meeting goals (Radek);
2. Novel CG techniques for CMB map-making (Thibault);
3. Bayesian sampling techniques for CMB (Gabriel);
4. Massively parallel CMB map-making code development status (Hamza);
5. Summary, concluding remarks and plans for the future (all).

10. Dec 14, 2021, kick-off of the fifth (and last this time for sure !) year of the project.

The meeting was held remotely via ZOOM.

Participants: N. Chopin (CREST/ENSAE), O. Balabanov (INRIA), S. Bicquard (APC), G. Ducroucq (CREST/ENSAE),  J. Errard (APC),  L. Grigori (INRIA), B. Jost (APC), C. Leloup (APC), M. Morshead (APC), A. Rizzieri (APC),  R. Stompor (APC)

Discussion topics:

1. Project status and meeting goals (Radek);
2. Randomized linear algebra (Oleg);
3. Bayesian sampling techniques for CMB – recap of recent results and new directions (Gabriel);
4. Massively parallel CMB map-making code and techniques (Simon);
5. Reports on work by other groups (Arianna, Magdy) – continued on Thursday, Dec 16;
6. Summary, concluding remarks and plans for the new project year (all).

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