# Properties

 Label 1805.2.a.k Level $1805$ Weight $2$ Character orbit 1805.a Self dual yes Analytic conductor $14.413$ Analytic rank $1$ Dimension $4$ CM no Inner twists $2$

# Related objects

Show commands: Magma / PariGP / SageMath

## Newspace parameters

comment: Compute space of new eigenforms

[N,k,chi] = [1805,2,Mod(1,1805)]

mf = mfinit([N,k,chi],0)

lf = mfeigenbasis(mf)

from sage.modular.dirichlet import DirichletCharacter

H = DirichletGroup(1805, base_ring=CyclotomicField(2))

chi = DirichletCharacter(H, H._module([0, 0]))

N = Newforms(chi, 2, names="a")

//Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code

chi := DirichletCharacter("1805.1");

S:= CuspForms(chi, 2);

N := Newforms(S);

 Level: $$N$$ $$=$$ $$1805 = 5 \cdot 19^{2}$$ Weight: $$k$$ $$=$$ $$2$$ Character orbit: $$[\chi]$$ $$=$$ 1805.a (trivial)

## Newform invariants

comment: select newform

sage: f = N[0] # Warning: the index may be different

gp: f = lf[1] \\ Warning: the index may be different

 Self dual: yes Analytic conductor: $$14.4129975648$$ Analytic rank: $$1$$ Dimension: $$4$$ Coefficient field: $$\Q(\zeta_{20})^+$$ comment: defining polynomial  gp: f.mod \\ as an extension of the character field Defining polynomial: $$x^{4} - 5x^{2} + 5$$ x^4 - 5*x^2 + 5 Coefficient ring: $$\Z[a_1, \ldots, a_{7}]$$ Coefficient ring index: $$1$$ Twist minimal: yes Fricke sign: $$1$$ Sato-Tate group: $\mathrm{SU}(2)$

## $q$-expansion

comment: q-expansion

sage: f.q_expansion() # note that sage often uses an isomorphic number field

gp: mfcoefs(f, 20)

Coefficients of the $$q$$-expansion are expressed in terms of a basis $$1,\beta_1,\beta_2,\beta_3$$ for the coefficient ring described below. We also show the integral $$q$$-expansion of the trace form.

 $$f(q)$$ $$=$$ $$q + ( - \beta_{3} + \beta_1) q^{3} - 2 q^{4} - q^{5} + (\beta_{2} + 1) q^{7} - 4 \beta_{2} q^{9}+O(q^{10})$$ q + (-b3 + b1) * q^3 - 2 * q^4 - q^5 + (b2 + 1) * q^7 - 4*b2 * q^9 $$q + ( - \beta_{3} + \beta_1) q^{3} - 2 q^{4} - q^{5} + (\beta_{2} + 1) q^{7} - 4 \beta_{2} q^{9} + (3 \beta_{2} - 1) q^{11} + (2 \beta_{3} - 2 \beta_1) q^{12} + (\beta_{3} - \beta_1) q^{13} + (\beta_{3} - \beta_1) q^{15} + 4 q^{16} + (3 \beta_{2} + 2) q^{17} + 2 q^{20} + \beta_{3} q^{21} + ( - 4 \beta_{2} - 1) q^{23} + q^{25} + ( - 5 \beta_{3} + \beta_1) q^{27} + ( - 2 \beta_{2} - 2) q^{28} + 2 \beta_{3} q^{29} + ( - \beta_{3} - 3 \beta_1) q^{31} + (7 \beta_{3} - 4 \beta_1) q^{33} + ( - \beta_{2} - 1) q^{35} + 8 \beta_{2} q^{36} + (5 \beta_{3} + \beta_1) q^{37} + (4 \beta_{2} - 3) q^{39} + (3 \beta_{3} - 5 \beta_1) q^{41} + ( - \beta_{2} - 9) q^{43} + ( - 6 \beta_{2} + 2) q^{44} + 4 \beta_{2} q^{45} + ( - 6 \beta_{2} - 5) q^{47} + ( - 4 \beta_{3} + 4 \beta_1) q^{48} + (\beta_{2} - 5) q^{49} + (4 \beta_{3} - \beta_1) q^{51} + ( - 2 \beta_{3} + 2 \beta_1) q^{52} + ( - \beta_{3} - 6 \beta_1) q^{53} + ( - 3 \beta_{2} + 1) q^{55} + ( - \beta_{3} + 2 \beta_1) q^{59} + ( - 2 \beta_{3} + 2 \beta_1) q^{60} + (2 \beta_{2} - 4) q^{61} - 4 q^{63} - 8 q^{64} + ( - \beta_{3} + \beta_1) q^{65} + ( - 2 \beta_{3} + 3 \beta_1) q^{67} + ( - 6 \beta_{2} - 4) q^{68} + ( - 7 \beta_{3} + 3 \beta_1) q^{69} + (3 \beta_{3} + 5 \beta_1) q^{71} - 11 q^{73} + ( - \beta_{3} + \beta_1) q^{75} + ( - \beta_{2} + 2) q^{77} + ( - 9 \beta_{3} - 3 \beta_1) q^{79} - 4 q^{80} + ( - 4 \beta_{2} + 7) q^{81} + ( - 6 \beta_{2} + 1) q^{83} - 2 \beta_{3} q^{84} + ( - 3 \beta_{2} - 2) q^{85} + (6 \beta_{2} - 2) q^{87} + 7 \beta_1 q^{89} - \beta_{3} q^{91} + (8 \beta_{2} + 2) q^{92} - 5 q^{93} + (5 \beta_{3} + \beta_1) q^{97} + (16 \beta_{2} - 12) q^{99}+O(q^{100})$$ q + (-b3 + b1) * q^3 - 2 * q^4 - q^5 + (b2 + 1) * q^7 - 4*b2 * q^9 + (3*b2 - 1) * q^11 + (2*b3 - 2*b1) * q^12 + (b3 - b1) * q^13 + (b3 - b1) * q^15 + 4 * q^16 + (3*b2 + 2) * q^17 + 2 * q^20 + b3 * q^21 + (-4*b2 - 1) * q^23 + q^25 + (-5*b3 + b1) * q^27 + (-2*b2 - 2) * q^28 + 2*b3 * q^29 + (-b3 - 3*b1) * q^31 + (7*b3 - 4*b1) * q^33 + (-b2 - 1) * q^35 + 8*b2 * q^36 + (5*b3 + b1) * q^37 + (4*b2 - 3) * q^39 + (3*b3 - 5*b1) * q^41 + (-b2 - 9) * q^43 + (-6*b2 + 2) * q^44 + 4*b2 * q^45 + (-6*b2 - 5) * q^47 + (-4*b3 + 4*b1) * q^48 + (b2 - 5) * q^49 + (4*b3 - b1) * q^51 + (-2*b3 + 2*b1) * q^52 + (-b3 - 6*b1) * q^53 + (-3*b2 + 1) * q^55 + (-b3 + 2*b1) * q^59 + (-2*b3 + 2*b1) * q^60 + (2*b2 - 4) * q^61 - 4 * q^63 - 8 * q^64 + (-b3 + b1) * q^65 + (-2*b3 + 3*b1) * q^67 + (-6*b2 - 4) * q^68 + (-7*b3 + 3*b1) * q^69 + (3*b3 + 5*b1) * q^71 - 11 * q^73 + (-b3 + b1) * q^75 + (-b2 + 2) * q^77 + (-9*b3 - 3*b1) * q^79 - 4 * q^80 + (-4*b2 + 7) * q^81 + (-6*b2 + 1) * q^83 - 2*b3 * q^84 + (-3*b2 - 2) * q^85 + (6*b2 - 2) * q^87 + 7*b1 * q^89 - b3 * q^91 + (8*b2 + 2) * q^92 - 5 * q^93 + (5*b3 + b1) * q^97 + (16*b2 - 12) * q^99 $$\operatorname{Tr}(f)(q)$$ $$=$$ $$4 q - 8 q^{4} - 4 q^{5} + 2 q^{7} + 8 q^{9}+O(q^{10})$$ 4 * q - 8 * q^4 - 4 * q^5 + 2 * q^7 + 8 * q^9 $$4 q - 8 q^{4} - 4 q^{5} + 2 q^{7} + 8 q^{9} - 10 q^{11} + 16 q^{16} + 2 q^{17} + 8 q^{20} + 4 q^{23} + 4 q^{25} - 4 q^{28} - 2 q^{35} - 16 q^{36} - 20 q^{39} - 34 q^{43} + 20 q^{44} - 8 q^{45} - 8 q^{47} - 22 q^{49} + 10 q^{55} - 20 q^{61} - 16 q^{63} - 32 q^{64} - 4 q^{68} - 44 q^{73} + 10 q^{77} - 16 q^{80} + 36 q^{81} + 16 q^{83} - 2 q^{85} - 20 q^{87} - 8 q^{92} - 20 q^{93} - 80 q^{99}+O(q^{100})$$ 4 * q - 8 * q^4 - 4 * q^5 + 2 * q^7 + 8 * q^9 - 10 * q^11 + 16 * q^16 + 2 * q^17 + 8 * q^20 + 4 * q^23 + 4 * q^25 - 4 * q^28 - 2 * q^35 - 16 * q^36 - 20 * q^39 - 34 * q^43 + 20 * q^44 - 8 * q^45 - 8 * q^47 - 22 * q^49 + 10 * q^55 - 20 * q^61 - 16 * q^63 - 32 * q^64 - 4 * q^68 - 44 * q^73 + 10 * q^77 - 16 * q^80 + 36 * q^81 + 16 * q^83 - 2 * q^85 - 20 * q^87 - 8 * q^92 - 20 * q^93 - 80 * q^99

Basis of coefficient ring in terms of $$\nu = \zeta_{20} + \zeta_{20}^{-1}$$:

 $$\beta_{1}$$ $$=$$ $$\nu$$ v $$\beta_{2}$$ $$=$$ $$\nu^{2} - 3$$ v^2 - 3 $$\beta_{3}$$ $$=$$ $$\nu^{3} - 3\nu$$ v^3 - 3*v
 $$\nu$$ $$=$$ $$\beta_1$$ b1 $$\nu^{2}$$ $$=$$ $$\beta_{2} + 3$$ b2 + 3 $$\nu^{3}$$ $$=$$ $$\beta_{3} + 3\beta_1$$ b3 + 3*b1

## Embeddings

For each embedding $$\iota_m$$ of the coefficient field, the values $$\iota_m(a_n)$$ are shown below.

For more information on an embedded modular form you can click on its label.

comment: embeddings in the coefficient field

gp: mfembed(f)

Label   $$\iota_m(\nu)$$ $$a_{2}$$ $$a_{3}$$ $$a_{4}$$ $$a_{5}$$ $$a_{6}$$ $$a_{7}$$ $$a_{8}$$ $$a_{9}$$ $$a_{10}$$
1.1
 −1.17557 −1.90211 1.90211 1.17557
0 −3.07768 −2.00000 −1.00000 0 −0.618034 0 6.47214 0
1.2 0 −0.726543 −2.00000 −1.00000 0 1.61803 0 −2.47214 0
1.3 0 0.726543 −2.00000 −1.00000 0 1.61803 0 −2.47214 0
1.4 0 3.07768 −2.00000 −1.00000 0 −0.618034 0 6.47214 0
 $$n$$: e.g. 2-40 or 990-1000 Significant digits: Format: Complex embeddings Normalized embeddings Satake parameters Satake angles

## Atkin-Lehner signs

$$p$$ Sign
$$5$$ $$1$$
$$19$$ $$1$$

## Inner twists

Char Parity Ord Mult Type
1.a even 1 1 trivial
19.b odd 2 1 inner

## Twists

By twisting character orbit
Char Parity Ord Mult Type Twist Min Dim
1.a even 1 1 trivial 1805.2.a.k 4
5.b even 2 1 9025.2.a.bi 4
19.b odd 2 1 inner 1805.2.a.k 4
95.d odd 2 1 9025.2.a.bi 4

By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
1805.2.a.k 4 1.a even 1 1 trivial
1805.2.a.k 4 19.b odd 2 1 inner
9025.2.a.bi 4 5.b even 2 1
9025.2.a.bi 4 95.d odd 2 1

## Hecke kernels

This newform subspace can be constructed as the intersection of the kernels of the following linear operators acting on $$S_{2}^{\mathrm{new}}(\Gamma_0(1805))$$:

 $$T_{2}$$ T2 $$T_{3}^{4} - 10T_{3}^{2} + 5$$ T3^4 - 10*T3^2 + 5

## Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ $$T^{4}$$
$3$ $$T^{4} - 10T^{2} + 5$$
$5$ $$(T + 1)^{4}$$
$7$ $$(T^{2} - T - 1)^{2}$$
$11$ $$(T^{2} + 5 T - 5)^{2}$$
$13$ $$T^{4} - 10T^{2} + 5$$
$17$ $$(T^{2} - T - 11)^{2}$$
$19$ $$T^{4}$$
$23$ $$(T^{2} - 2 T - 19)^{2}$$
$29$ $$T^{4} - 20T^{2} + 80$$
$31$ $$T^{4} - 50T^{2} + 125$$
$37$ $$T^{4} - 130T^{2} + 4205$$
$41$ $$T^{4} - 170T^{2} + 4805$$
$43$ $$(T^{2} + 17 T + 71)^{2}$$
$47$ $$(T^{2} + 4 T - 41)^{2}$$
$53$ $$T^{4} - 185T^{2} + 4205$$
$59$ $$T^{4} - 25T^{2} + 125$$
$61$ $$(T^{2} + 10 T + 20)^{2}$$
$67$ $$T^{4} - 65T^{2} + 605$$
$71$ $$T^{4} - 170T^{2} + 5$$
$73$ $$(T + 11)^{4}$$
$79$ $$T^{4} - 450 T^{2} + 49005$$
$83$ $$(T^{2} - 8 T - 29)^{2}$$
$89$ $$T^{4} - 245 T^{2} + 12005$$
$97$ $$T^{4} - 130T^{2} + 4205$$