# Properties

 Label 8.21.d Level 8 Weight 21 Character orbit d Rep. character $$\chi_{8}(3,\cdot)$$ Character field $$\Q$$ Dimension 19 Newforms 2 Sturm bound 21 Trace bound 1

# Related objects

## Defining parameters

 Level: $$N$$ = $$8 = 2^{3}$$ Weight: $$k$$ = $$21$$ Character orbit: $$[\chi]$$ = 8.d (of order $$2$$ and degree $$1$$) Character conductor: $$\operatorname{cond}(\chi)$$ = $$8$$ Character field: $$\Q$$ Newforms: $$2$$ Sturm bound: $$21$$ Trace bound: $$1$$ Distinguishing $$T_p$$: $$3$$

## Dimensions

The following table gives the dimensions of various subspaces of $$M_{21}(8, [\chi])$$.

Total New Old
Modular forms 21 21 0
Cusp forms 19 19 0
Eisenstein series 2 2 0

## Trace form

 $$19q + 626q^{2} - 2q^{3} + 1773556q^{4} + 25323676q^{6} - 2031549544q^{8} + 19758444937q^{9} + O(q^{10})$$ $$19q + 626q^{2} - 2q^{3} + 1773556q^{4} + 25323676q^{6} - 2031549544q^{8} + 19758444937q^{9} + 742754160q^{10} - 14520628706q^{11} - 92518091912q^{12} - 431248136928q^{14} + 140976757264q^{16} + 990389375398q^{17} + 5272759222774q^{18} - 1375336086082q^{19} - 32520172742880q^{20} - 109675699217572q^{22} + 144938556063376q^{24} - 300360045368285q^{25} + 154289718058128q^{26} - 514588541331140q^{27} - 394619539621440q^{28} + 223250517248160q^{30} - 1707914682142624q^{32} - 379273727638900q^{33} - 4373483391631324q^{34} + 3615863153468160q^{35} + 11585741011529500q^{36} + 11866377694661788q^{38} + 11813880412973760q^{40} - 8427241614192506q^{41} + 38127588900300480q^{42} - 24717352370364898q^{43} - 11262977142561032q^{44} - 21739818881100192q^{46} + 153956946591726688q^{48} - 173173121721250637q^{49} + 139361869584456530q^{50} - 417243550710750724q^{51} - 44583718369992480q^{52} + 131060624290419256q^{54} - 505574909383001472q^{56} - 638353406270838580q^{57} - 677523738697093680q^{58} - 80800002484130978q^{59} + 1631640690429240000q^{60} + 1780090172849178240q^{62} + 1328363317618417216q^{64} + 1575343920200472960q^{65} + 3043614561170466056q^{66} - 1808783156240800642q^{67} - 2362666796221870232q^{68} - 6151558949299572480q^{70} + 4959295908955144264q^{72} + 3866104143546483398q^{73} - 5642095430673385488q^{74} + 24308156015351409310q^{75} - 9480723535297927816q^{76} - 14599907290310144160q^{78} - 22104885212702947200q^{80} + 13599596957313525631q^{81} - 15707154812006670172q^{82} - 77448386448570160322q^{83} + 17095266896298568320q^{84} + 36403346004507897820q^{86} - 13164074256796170352q^{88} + 33127276190960144518q^{89} - 33204348719592139440q^{90} + 161045136122144660736q^{91} - 932896292396925120q^{92} - 107259275077774974528q^{94} + 197187886676221266496q^{96} + 77267514659308382822q^{97} + 236544665851892453426q^{98} - 342412845288286744966q^{99} + O(q^{100})$$

## Decomposition of $$S_{21}^{\mathrm{new}}(8, [\chi])$$ into irreducible Hecke orbits

Label Dim. $$A$$ Field CM Traces $q$-expansion
$$a_2$$ $$a_3$$ $$a_5$$ $$a_7$$
8.21.d.a $$1$$ $$20.281$$ $$\Q$$ $$\Q(\sqrt{-2})$$ $$1024$$ $$114226$$ $$0$$ $$0$$ $$q+2^{10}q^{2}+114226q^{3}+2^{20}q^{4}+\cdots$$
8.21.d.b $$18$$ $$20.281$$ $$\mathbb{Q}[x]/(x^{18} + \cdots)$$ None $$-398$$ $$-114228$$ $$0$$ $$0$$ $$q+(-22+\beta _{1})q^{2}+(-6347-5\beta _{1}+\cdots)q^{3}+\cdots$$