Atelier 2020

Previous Ateliers:

2015 (Bordeaux), 2016 (Grenoble), 2017 (Lyon) 2017b (Clermont-Ferrand) 2017c (Oujda) 2018 (Besançon) 2018b (Roma) 2019 (Bordeaux) 2019b (Roma)

Welcome to Atelier PARI/GP 2020 (Grenoble)

Tasks

  • doctesting (Marine, Valentin, Mohamed, Cyril, Razvan, Anne-Edgar, Samuele, Baptiste, Julien, Paul) (many reports, some already incorporated)
  • Philippe (pari tutorial for teachers: arithmetics, algebra etc)
  • Xavier (p-adic L-functions) (Iwasawa series working for zeta)
  • Jared (morphisms between finite abelian groups) (discussions with KB and Andreas about abelian groups, in progress)
  • Andreas (modular polynomials) (computed a modular polynomial, discussed CM theory and groups; debugging paritwine)
  • Karim (supervise doctesting, help everyone)
  • Henri (help people)
  • Roland (parallel computing) (linking pari and GPUs with cypari; quite hard! problems with pari and jupyter; use cypari?)
  • Francesco (enumeration of number fields with prescribed ramification) (trying to use some congruences for quintics; progress)
  • Aurel (Hecke characters, p-adic fields) (found and fixed bugs, broke everything)
  • Titouan (elliptic curves) (work on a benchmark)
  • Maiga (hyperelliptic curves, elliptic curves) (tests with invariants, seems to work, used the software-we-cannot-name)
  • Razvan (mf, modular poly) (computed a modular polynomial with Andreas, finishing slides)
  • Denys (parallel computing) (working with Vinko)
  • Samuele (modular forms, modular symbols, isomorphism of Galois representations) (talked to people)
  • Nicolas (congruences between modular forms, mfsearch) (learning how to make patches)
  • Baptiste (modular forms) (working on the small image project, talk, working with KB)
  • Etienne (LLL over number fields) (finished quadratic case, slides, talk)
  • Christelle (exploration of pari) (root localisation, extending to special types of polynomials, wrong algorithm -> make it correct)
  • Vinko (computations with factorisations) (trying parallel programming with MPI)
  • Richard (discover pari, elliptic curves over function fields) (<- did this)
  • Julien (discover pari, number fields) (slacking off)
  • Francois (compute Eisenstein series, products of such) (<- worked on this, found a mistake in a paper)
  • Bernadette (modular symbols) (worked with Francois)
  • Pascal (Hecke characters) (worked with Aurel, debugging paritwine)
  • Bill (discriminants of relative polynomials) (test case provided by Jared was wrong, relative polynomial discriminant, correct test case works in 10min instead of 1h)
  • Bernard (interface between Xcas and pari)

Planning for next stable release (2.13.0-stable)

Feature requests

  • ellfactorback
  • foreach
  • allow lexical variables (my) to have the same name as a built-in function (original problem: scripts break when we add new functions)
  • nfinit: flag without LLL

Future projects (significant work needed)

  • Wishlist items in the bug tracking system
  • LU decomposition of matrices (Peter Bruin)
  • algebraic lattices: LLL, qfauto, qfisom (Thomas Camus, Cyril Hugounenq, Titouan Coladon, Etienne Marcatel, Thomas Mégarbané, Aurel Page)
  • merge the existing t_REAL branches (?); remove incompatibility with polgalois (Karim Belabas)
  • primepi (Dana Jacobsen)
  • rnfsplitting
  • help search with regular expressions (KB)
  • other fplll algorithms?
  • BKZ, SVP, HKZ, CVP…
  • make qfminim rigorous
  • p-adic fields
  • faster weight 1 forms with modular arithmetic
  • better polgalois
  • parallelize MPQS
  • parallelize linear algebra
  • parallelize multiplication table in nf
  • rnfinit without maximal order
  • check where we should use fast matrix multiplication

Future projects (to be finalized)

  • helpsearch: find function names / doc content matching some kind of regular expression (trivial flag to gphelp: what to do with the output ?)
  • Hecke characters of infinite order (Pascal Molin, Aurel Page) [almost done]
  • integrate Denis’s 2-descent scripts (Bill, KB)
  • mfgaloisrep for weight 1 (Bill, Aurel)
  • permconjugate, cycle decomposition, functions for permutation groups (exists: what to export?)
  • Takashi Fukuda’s package (Iwasawa theory / p-class groups of abelian fields)
  • half-gcd
  • abelian groups (Jared)
  • root localisation (Christelle) localization.gp pol_tests.gp
  • congruences between modular forms (Baptiste)
  • HGM
  • zetafast
  • numerical analysis

Long-term feature requests

  • nfinit for large degree number fields (say ~500). Problem: which functionalities should work?

Next workshops

  • 05/2020: Roma

  • 06/2020: Luxembourg

  • 01/2021: Besançon

  • 01/2022: Marseille ?

  • 01/2023: Lyon (ENS) ?