Properties

Label 2.3_2557.7t2.1
Dimension 2
Group $D_{7}$
Conductor $ 3 \cdot 2557 $
Frobenius-Schur indicator 1

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Basic invariants

Dimension:$2$
Group:$D_{7}$
Conductor:$7671= 3 \cdot 2557 $
Artin number field: Splitting field of $f= x^{7} + 7 x^{5} - 6 x^{4} - 98 x^{3} - 309 x^{2} - 375 x - 225 $ over $\Q$
Size of Galois orbit: 3
Smallest containing permutation representation: $D_{7}$
Parity: Odd

Galois action

Roots of defining polynomial

The roots of $f$ are computed in an extension of $\Q_{ 23 }$ to precision 5.
Minimal polynomial of a generator $a$ of $K$ over $\mathbb{Q}_{ 23 }$: $ x^{2} + 21 x + 5 $
Roots:
$r_{ 1 }$ $=$ $ 5 + 17\cdot 23 + 14\cdot 23^{2} + 13\cdot 23^{4} +O\left(23^{ 5 }\right)$
$r_{ 2 }$ $=$ $ 15 a + 17 + \left(17 a + 21\right)\cdot 23 + \left(6 a + 18\right)\cdot 23^{2} + \left(2 a + 20\right)\cdot 23^{3} + \left(13 a + 7\right)\cdot 23^{4} +O\left(23^{ 5 }\right)$
$r_{ 3 }$ $=$ $ 5 a + 18 + \left(17 a + 20\right)\cdot 23 + \left(22 a + 17\right)\cdot 23^{2} + \left(13 a + 2\right)\cdot 23^{3} + \left(15 a + 10\right)\cdot 23^{4} +O\left(23^{ 5 }\right)$
$r_{ 4 }$ $=$ $ 10 a + 13 + \left(4 a + 16\right)\cdot 23 + \left(17 a + 20\right)\cdot 23^{2} + \left(18 a + 21\right)\cdot 23^{3} + \left(13 a + 7\right)\cdot 23^{4} +O\left(23^{ 5 }\right)$
$r_{ 5 }$ $=$ $ 8 a + 1 + \left(5 a + 19\right)\cdot 23 + \left(16 a + 14\right)\cdot 23^{2} + \left(20 a + 18\right)\cdot 23^{3} + \left(9 a + 8\right)\cdot 23^{4} +O\left(23^{ 5 }\right)$
$r_{ 6 }$ $=$ $ 18 a + 5 + \left(5 a + 4\right)\cdot 23 + \left(9 a + 8\right)\cdot 23^{3} + \left(7 a + 4\right)\cdot 23^{4} +O\left(23^{ 5 }\right)$
$r_{ 7 }$ $=$ $ 13 a + 10 + \left(18 a + 15\right)\cdot 23 + \left(5 a + 4\right)\cdot 23^{2} + \left(4 a + 19\right)\cdot 23^{3} + \left(9 a + 16\right)\cdot 23^{4} +O\left(23^{ 5 }\right)$

Generators of the action on the roots $r_1, \ldots, r_{ 7 }$

Cycle notation
$(1,7)(2,6)(3,4)$
$(1,2)(3,7)(4,5)$

Character values on conjugacy classes

SizeOrderAction on $r_1, \ldots, r_{ 7 }$ Character values
$c1$ $c2$ $c3$
$1$ $1$ $()$ $2$ $2$ $2$
$7$ $2$ $(1,7)(2,6)(3,4)$ $0$ $0$ $0$
$2$ $7$ $(1,3,5,4,7,2,6)$ $-\zeta_{7}^{5} - \zeta_{7}^{4} - \zeta_{7}^{3} - \zeta_{7}^{2} - 1$ $\zeta_{7}^{4} + \zeta_{7}^{3}$ $\zeta_{7}^{5} + \zeta_{7}^{2}$
$2$ $7$ $(1,5,7,6,3,4,2)$ $\zeta_{7}^{5} + \zeta_{7}^{2}$ $-\zeta_{7}^{5} - \zeta_{7}^{4} - \zeta_{7}^{3} - \zeta_{7}^{2} - 1$ $\zeta_{7}^{4} + \zeta_{7}^{3}$
$2$ $7$ $(1,4,6,5,2,3,7)$ $\zeta_{7}^{4} + \zeta_{7}^{3}$ $\zeta_{7}^{5} + \zeta_{7}^{2}$ $-\zeta_{7}^{5} - \zeta_{7}^{4} - \zeta_{7}^{3} - \zeta_{7}^{2} - 1$
The blue line marks the conjugacy class containing complex conjugation.