# Previous Ateliers:
[2015 (Bordeaux)](Atelier%202015),
[2016 (Grenoble)](Atelier%202016),
[2017 (Lyon)](Atelier%202017)
[2017b (Clermont-Ferrand)](Atelier%202017b)
[2017c (Oujda)](Atelier%202017c)
[2018 (Besançon)](Atelier%202018)
[2018b (Roma)](Atelier%202018b)
[2019 (Bordeaux)](Atelier%202019)
[2019b (Roma)](Atelier%202019b)
[2020 (Grenoble)](Atelier%202020)
[2021b (Oujda)](Atelier%202021b)
[2022 (Besançon)](Atelier%202022)
[2023 (CIRM)](Atelier%202023)
[2024 (Lyon)](Atelier%202024)
[2024b (Roma)](Atelier%202024b)
[2025 (Orsay)](Atelier%202025)
[LIBPARI2025 (Bordeaux)](Libpari%202025)

# [Welcome to Atelier PARI/GP 2026 (Bordeaux)](https://pari.math.u-bordeaux.fr/Events/PARI2026/)

[doctesting](doc2026)

## Topics

- Eric      : local units mod p and unramified extensions, done! (demo)
- Haetham   : snf forms etc.
- Bill      : helping around, fixed 2 bugs (demo of polynomial linear recurrence script)
- Salma     : doctesting, elliptic curves over number fields, crypto, CRT
- Rayane    : presentations by coverings, slides
- Safia     : doctesting, using git
- Daniel    : snf stuff, homology computations (demo)
- Nicolas B.: congruences between modular forms, CM modular forms
- Zakariae  : Eisenstein series attached to quadratic fields, mf package (demo)
- Alina     : factorisation of Hecke L-functions in terms of Dirichlet L-functions
- Henri     : helping around, modular forms from quadratic fields (demo), improving mfshimura
- Mateo     : computing coefficients of generating series
- Alejandro : Voronoi complex
- Philippe  : cohomology of arithmetic groups
- Tim       : trying things, reading doc, finite topological spaces (demo)
- Andreas   : scheme bindings for the pari library [compiles then crashes], reading doc
- Fabrice   : class group computations with norm relations
- Sam       : 3 and 5 descent, coverings
- Pengju    : charpoly of Frobenius of varieties, p-adic regulators
- David     : helping, doctesting, tutorials, p-adic extensions
- Tao       : reading tutorials, SNF
- Gabriel   : Voronoi's algorithm for Hermitian forms
- Rob       : doctesting (bnfinit), p-adic polylogs
- Fredrik   : benchmarking primality tests - [profiling](profiling2026)
- Kiran     : joining others, hypergeometric motives, abelianbnf, sparse matrices
- Antoine   : polynomial factorisation over Fp
- Afonso    : discrete gaussian in lattices, testing (demo)
- Nicolas M.: algebraic curves, looking for volunteers to help
- Thibaut   : doctesting, theta characteristics of jacobians
- Pascal    : artin representations, mfsaturate (demo)
- Pierre M. : class field theory, p-adic fields, bnfinit
- Aurel     : helping around
- Baptiste  : modular forms, congruences, class field theory, projective Artin representations (demo)
- Alice     : S-units with norm relations, bnfinit and residue of the Dedekind zeta function
- Bernadette: doctesting, reading
- Fotios    : doctesting, action on additive structure of ideals
- Damien    : experiments on formulas for elliptic curves
- Marine    : doctesting
- Denis     : Mahler measure of polynomials: 1 variable, 2 variables; helping around (demo?)
- Julien    : elliptic curves over finite fields and quaternion algebras; localising quaternion algebras (demo)
- Giacomo   : elliptic curves over number fields
- Alexander : automorphism groups of fields, alnuth, second cohomology for polycyclic groups in GAP, compute the action
- Wenwen    : Verify the correctness of reduction between RLWE and MP-LWE


## Next ateliers

- 2027 Clermont-Ferrand
- 2028 ??

## Planning for 2.19

- statistics (statinit, characteristic function = Fourier transform)
- Riemann theta (Jean Kieffer)
- Heegner points on twists
- Harvey-Sutherland
- polmahler
- mfeisensteinnf, mfsaturate

## Planning for 2.21

- curves (Nicolas)
- p-adic fields (Aurel, Bill, Leo)
- Fuchsian groups (James, Rayane, Aurel)
- dim 2 Artin reps (Bill, Aurel) nflist("A4cond" / "S4cond")
- abelianbnf / bnrclassgroup (Aurel)
- mfcongruence (Baptiste, Nicolas B.)

## Long term projects

- rewrite Galois groups (polgalois)
- Massey products and cup products (Eric, since 2025)
- Gentry-Szydlo algorithm (Bill, Alice, Andreas)
- sparse matrices (Aurel)
- Satoh algorithm, Damien and Abdoulaye's version

## Wishlist

- faster factorization of bivariate polynomials over finite field.
- idealstarmap (same as bnrmap but for idealstar)
- map (ZK/pr^k)* -> Cl_F(N) for pr^k||N (name? bnrlocalunits?)
- gchar -> mf
- random element of Gamma_0(N)
- [Wishlist items in the bug tracking system](http://pari.math.u-bordeaux.fr/cgi-bin/pkgreport.cgi?pkg=pari#_0_4_4)

## Checklist of TODOs from 2025 Atelier

- algebraic curves (Nicolas, since 2024)
- [x] n-th roots in finite fields (Marton)
- isomorphism and splitting of quaternion algebras (Péter, Denis) Suggestions: isomorphism of quadratic spaces, addition in the Brauer group

## Future projects (long term)

- p-adic fields (Aurel, Leo, since 2020) wishlist: Compute extensions (effective Krasner's lemma), compositum of extensions, finding a uniformizer and determine wether the extension is Galois. Decompose extension as totally ramified over unramified extension of Qp. Function like padicfield but starting from any p-adic field. Factoring polynomials over any p-adic field. Classical transcendental functions (over any p-adic field): log, exp, polylogs. Solutions of differential equations. Creating unramified extension of Qp of degree d from F_{p^d} (Witt vectors W(F_p^d)). Local class field theory: structure of units and construction of abelian extensions.
- p-adic polylogs (Bill, Aurel, Rob)

## Feature requests
- functions for manipulating finitely generated Abelian groups
- polmahler: Mahler measure of polynomials in 1 and 2 variables, over C (Denis)
- random generation for various distributions
- computing spherical polynomials

## Checklist of Future projects from 2024 Atelier (significant work needed)

- qfauto using roots (Olivier)
- inner twists of mf (François)
- norm relations (Aurel, Fabrice)
- higher-dimensional isogenies (Pierrick)
- mod p mf / congruences between modular forms (Baptiste, since 2020)
- quaternion algebras functionalities from SQISign (Benjamin)
- splitting of algebras (Mickaël, Aurel)
- include James Rickards code for fundamental domains (Aurel)

## Feature requests

- foreach(L,[a,b],...)
- export coprime factorisation, cf ?? "Coprime factorization"@
    factorcoprime
    coprimepart
- interface gcharidentify with prec argument (like lindep)
- gchar: algebraic characters with algebraic evaluation: one char, one field per modulus, one field (+cyclotomic) per bnf, p-adic evaluation.
- gchar: change of field (two directions)
- gchareval: how to obtain the chosen uniformiser? / evaluating the local
  character at a p-adic place (nfeltval + ideallog)
  gcharlocaleval?
- courbe ell CM -> gchar
- nfiscm (if the cm involution exists then you know it in all the embeddings so you can reconstruct it)
- give a starting non-maximal order to nfinit
- matrix groups over finite fields
- Coleman integration
- Fourier transform of finite abelian groups

## Checklist of TODOs from 2020 Atelier

### Future projects (significant work needed)

- 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)
- BKZ
- HKZ
- make qfminim rigorous
- parallelize MPQS
- parallelize multiplication table in nf
- rnfinit without maximal order (KB: definitely not available under GP. Cf nf_rnfeq & nf_rnfeqsimple).

### 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 ?)
- mfgaloisrep for weight 1 (Bill, Aurel)
- permconjugate, functions for permutation groups (exists: what to export?)
- abelian groups (Jared)
- root localisation (Christelle) [localization.gp](/localization.gp)
  [pol_tests.gp](/pol_tests.gp)

### Long-term feature requests

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

## Checklist of TODOs from 2019 Atelier

- ffintersect, ffcompositum, ffsubfield, ffsplitting (Bill)