atlas Library · Script File
nilpotent_posets.at
closure relations for nilpotent orbits
Definitions in source order
NilpotentPoset type
set_type NilpotentPoset = (RootDatum root_datum, [ComplexNilpotent] orbits, Poset orbit_closures)
Fields: root_datum, orbits, orbit_closures
list of complex orbits and their closure relations
nilpotent_poset
nilpotent_poset ((RootDatum, [ComplexNilpotent], Poset)triple) = NilpotentPosetidentity, for now
also defined in exceptional.at
sort
sort = ([ComplexNilpotent] -> [ComplexNilpotent])sort by dimension
also defined in sommers.at, sort.at, hodge_functions.at
find
find([ComplexNilpotent] orbits,ComplexNilpotent O) = intalso defined in basic.at, tits_centralizer.at, nilpotent_orbits.at, cells.at, K_types.at, hodgeParamLaurentPol.at, extended.at, disconnected.at, K_types_plus.at
these next two functions should be done along the lines of sort_u in sort.atL24
eliminate_duplicates
eliminate_duplicates([ComplexNilpotent] orbits) = [ComplexNilpotent]sort_u
sort_u ([ComplexNilpotent] orbits) = [ComplexNilpotent]also defined in sort.at, K_types.at
saturate
saturate (NilpotentPoset P,RootDatum rd) = NilpotentPosetsaturate the orbits of L together with their closure relations
also defined in nilpotent_orbits.at, disconnected.at
merge
merge(NilpotentPoset P,NilpotentPoset Q) = ([ComplexNilpotent],[[int]])combine two complex nilpotent posets P=(orbits_P,posets_P) Q=(orbits_Q,posets_Q) new_orbit: sort_u(orbits_P##orbits_Q) new_posets: relations on new_orbits coming from posets_P and posets_Q
also defined in sort.at
submerge
submerge(NilpotentPoset P,NilpotentPoset Q)variant of merge: assuming: P.orbits\subset Q.orbits application: Q is all orbits for rd (and some relations) submerge adds the relations from P, more efficient than using merge in this case
seed_complex_nilpotent_poset
seed_complex_nilpotent_poset(RootDatum rd) = NilpotentPosetseed with (list of complex nilpotents, trivial relations) trivial relations: 0 < everything < principal
other elementary relations: simple case: 0<minimal < others < subregular < principal this induces relations in the non-simple caseL112
fill_nilpotent_posets_subregular
fill_nilpotent_posets_subregular(NilpotentPoset P) = NilpotentPosetgiven poset of nilpotents, add the relations coming from the subregular orbits
fill_nilpotent_posets_minimal
fill_nilpotent_posets_minimal(NilpotentPoset P) = NilpotentPosetgiven poset of nilpotents, add the relations coming from the minimal orbits
starting_complex_nilpotent_poset
starting_complex_nilpotent_poset(RootDatum rd) = NilpotentPosetstarting point: list of complex nilpotents closure relations from 0 and principal orbits (seed) closure relations from subregular orbits (fill_nilpotent_posets_subregular) closure relations from minimal orbits (fill_nilpotent_posets_minimal)
nilpotent_orbits_and_closures
nilpotent_orbits_and_closures(RootDatum rd) = NilpotentPosetgraph
graph(NilpotentPoset P) = stringgraph of NilpotentPoset this is the graph of the poset, together with labels (H,dimension) from the orbits see exceptional.at for a version using a NilpotentTable for the names
also defined in poset.at, exceptional.at
special_elliptic
special_elliptic(RootDatum rd)lusztig_of_special_elliptic 2 overloads
lusztig_of_special_elliptic(WeylElt w) = ComplexNilpotentlusztig_of_special_elliptic(RootDatum rd,ratvec v) = ComplexNilpotentg
g(WeylElt w)also defined in laurentPolynomial.at
sort_by_dimension_of_nilpotent
sort_by_dimension_of_nilpotent = ([WeylElt] -> [WeylElt])sort [WeylElt] by dimension of Lusztig(w) (associated nilpotent), assuming each w is special elliptic so Lusztig(w) is known
special_elliptic_poset
special_elliptic_poset(RootDatum rd) = NilpotentPosetmaster_complex_nilpotent_poset
master_complex_nilpotent_poset(RootDatum rd) = NilpotentPosetnilpotent_orbits_and_closures_saturate
rec_fun nilpotent_orbits_and_closures_saturate(RootDatum rd) = NilpotentPosetsimple_induce
simple_induce(RootDatum rd,NilpotentPoset P) = NilpotentPosetassume P is for a Levi
also defined in nilpotent_induction.at
nilpotent_orbits_and_closures_induce
rec_fun nilpotent_orbits_and_closures_induce(RootDatum rd) = NilpotentPosettest
test(NilpotentPoset P) = [int,int]also defined in test_unitarity.at, all_finite_order.at, nilpotent_centralizer.at, sommers.at, tensor_product.at
nilpotent_orbits_and_closures_test
rec_fun nilpotent_orbits_and_closures_test(RootDatum rd, int N) = NilpotentPosetfor testing: just go up to N
show 2 overloads
show(NilpotentPoset P) = voidshow([RootDatum] subs,[NilpotentPoset] orbit_posets) = voidalso defined in modules.at, K_Nilpotent.at, good_W_representatives.at, arthur_parameters.at, sub_cells.at, associated_variety_annihilator.at, geck_generic.at, L_packet.at, ratmat.at, Levi_subgroups.at, nilpotent_orbits.at, subgroups.at, poset.at, cyclotomic.at, polynomial.at, character_tables.at, springer_tables.at, hodgeParamLaurentPol.at, hodgeParamPol.at, laurentPolynomial.at, weak_packets.at, cyclotomic_Lie_algebra.at, cyclotomicMat.at, bracket.at, exceptional.at, lazy_lists.at
show_subgroup_orbit_nilpotent_map
show_subgroup_orbit_nilpotent_map(RootDatum rd) = voidGenerated from atlas-scripts at commit 648506c (2026-10-13).