Abelian variety isogeny class 2.71.a_ew over $\F_{71}$

• Label: 2.71.a_ew
• Base field: $\F_{71}$
• Dimension: $2$
• $p$-rank: $2$
• Ordinary: yes
• Supersingular: no
• Simple: no
• Geometrically simple: no
• Primitive: yes
• Principally polarizable: yes
• Contains a Jacobian: yes

Invariants

Base field:	$\F_{71}$
Dimension:	$2$
L-polynomial:	$( 1 - 4 x + 71 x^{2} )( 1 + 4 x + 71 x^{2} )$
	$1 + 126 x^{2} + 5041 x^{4}$
Frobenius angles:	$\pm0.423719104038$, $\pm0.576280895962$
Angle rank:	$1$ (numerical)
Jacobians:	$77$
Cyclic group of points:	no
Non-cyclic primes:	$2$

This isogeny class is not simple, primitive, ordinary, and not supersingular. It is principally polarizable and contains a Jacobian.

Newton polygon

This isogeny class is ordinary.

$p$-rank:	$2$
Slopes:	$[0, 0, 1, 1]$

Point counts

Point counts of the abelian variety

$r$	$1$	$2$	$3$	$4$	$5$
$A(\F_{q^r})$	$5168$	$26708224$	$128100378800$	$645459145068544$	$3255243548357732528$

Point counts of the curve

$r$	$1$	$2$	$3$	$4$	$5$	$6$	$7$	$8$	$9$	$10$
$C(\F_{q^r})$	$72$	$5294$	$357912$	$25400094$	$1804229352$	$128100473678$	$9095120158392$	$645753565751614$	$45848500718449032$	$3255243545705583854$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 77 curves (of which all are hyperelliptic):

• $y^2=46 x^6+36 x^5+48 x^4+8 x^3+44 x^2+47 x+42$
• $y^2=38 x^6+39 x^5+52 x^4+56 x^3+24 x^2+45 x+10$
• $y^2=43 x^6+4 x^5+57 x^4+69 x^3+36 x^2+66 x+70$
• $y^2=59 x^6+45 x^5+55 x^4+45 x^3+55 x^2+45 x+59$
• $y^2=58 x^6+31 x^5+30 x^4+31 x^3+30 x^2+31 x+58$
• $y^2=16 x^6+57 x^5+55 x^4+19 x^3+52 x+34$
• $y^2=41 x^6+44 x^5+30 x^4+62 x^3+9 x+25$
• $y^2=50 x^6+56 x^5+70 x^4+42 x^3+25 x^2+44 x+20$
• $y^2=2 x^6+56 x^5+36 x^4+16 x^3+50 x^2+23 x+1$
• $y^2=14 x^6+37 x^5+39 x^4+41 x^3+66 x^2+19 x+7$
• $y^2=17 x^6+44 x^5+8 x^4+61 x^3+59 x^2+28 x+58$
• $y^2=21 x^6+36 x^5+19 x^4+69 x^3+49 x^2+13 x+14$
• $y^2=32 x^6+66 x^5+47 x^4+61 x^3+21 x^2+48 x+34$
• $y^2=11 x^6+36 x^5+45 x^4+x^3+5 x^2+52 x+25$
• $y^2=22 x^6+24 x^5+16 x^4+24 x^3+60 x^2+7 x+69$
• $y^2=12 x^6+26 x^5+41 x^4+26 x^3+65 x^2+49 x+57$
• $y^2=7 x^6+24 x^4+26 x^2+58$
• $y^2=66 x^6+18 x^4+55 x^2+60$
• $y^2=59 x^6+24 x^5+11 x^4+66 x^3+65 x^2+70 x+70$
• $y^2=58 x^6+26 x^5+6 x^4+36 x^3+29 x^2+64 x+64$
• and

• $y^2=9 x^6+9 x^5+20 x^4+68 x^3+7 x^2+54 x+13$
• $y^2=63 x^6+63 x^5+69 x^4+50 x^3+49 x^2+23 x+20$
• $y^2=54 x^6+41 x^5+29 x^4+31 x^3+70 x^2+25 x+21$
• $y^2=23 x^6+3 x^5+61 x^4+4 x^3+64 x^2+33 x+5$
• $y^2=57 x^6+32 x^5+52 x^4+3 x^3+52 x^2+32 x+57$
• $y^2=44 x^6+11 x^5+9 x^4+21 x^3+9 x^2+11 x+44$
• $y^2=36 x^6+43 x^5+13 x^4+7 x^3+61 x^2+12 x+54$
• $y^2=39 x^6+17 x^5+20 x^4+49 x^3+x^2+13 x+23$
• $y^2=31 x^6+36 x^4+39 x^2+54$
• $y^2=42 x^6+6 x^4+42 x^2+64$
• $y^2=52 x^6+63 x^5+54 x^4+23 x^3+54 x^2+63 x+52$
• $y^2=9 x^6+15 x^5+23 x^4+19 x^3+23 x^2+15 x+9$
• $y^2=67 x^6+7 x^5+42 x^4+64 x^3+23 x^2+32 x+54$
• $y^2=43 x^6+49 x^5+10 x^4+22 x^3+19 x^2+11 x+23$
• $y^2=58 x^6+14 x^4+27 x^2+14$
• $y^2=15 x^6+28 x^4+54 x^2+33$
• $y^2=58 x^6+44 x^5+30 x^4+42 x^3+59 x^2+50 x+49$
• $y^2=51 x^6+24 x^5+68 x^4+10 x^3+58 x^2+66 x+59$
• $y^2=27 x^6+35 x^5+12 x^4+52 x^3+54 x^2+24 x+42$
• $y^2=47 x^6+32 x^5+13 x^4+9 x^3+23 x^2+26 x+10$
• $y^2=38 x^6+52 x^5+64 x^4+37 x^3+44 x^2+47 x+12$
• $y^2=45 x^6+65 x^5+5 x^4+31 x^3+5 x^2+14 x+67$
• $y^2=31 x^6+29 x^5+35 x^4+4 x^3+35 x^2+27 x+43$
• $y^2=44 x^6+12 x^5+13 x^4+61 x^3+47 x^2+43 x+53$
• $y^2=24 x^6+13 x^5+20 x^4+x^3+45 x^2+17 x+16$
• $y^2=2 x^6+61 x^5+12 x^4+23 x^3+37 x^2+34 x+15$
• $y^2=14 x^6+x^5+13 x^4+19 x^3+46 x^2+25 x+34$
• $y^2=42 x^6+64 x^5+12 x^4+16 x^3+22 x+9$
• $y^2=10 x^6+22 x^5+13 x^4+41 x^3+12 x+63$
• $y^2=62 x^6+64 x^5+56 x^4+34 x^3+44 x^2+47 x+28$
• $y^2=8 x^6+22 x^5+37 x^4+25 x^3+24 x^2+45 x+54$
• $y^2=51 x^6+17 x^5+24 x^4+65 x^3+24 x^2+17 x+51$
• $y^2=2 x^6+48 x^5+26 x^4+29 x^3+26 x^2+48 x+2$
• $y^2=20 x^6+12 x^5+70 x^4+52 x^3+4 x^2+46 x+8$
• $y^2=69 x^6+13 x^5+64 x^4+9 x^3+28 x^2+38 x+56$
• $y^2=37 x^6+18 x^5+5 x^4+41 x^3+24 x^2+55 x+30$
• $y^2=20 x^6+55 x^5+41 x^4+5 x^3+50 x^2+66 x+31$
• $y^2=6 x^6+65 x^5+62 x^4+40 x^3+59 x^2+54 x+32$
• $y^2=18 x^6+16 x^5+39 x^4+7 x^3+23 x^2+44 x+70$
• $y^2=55 x^6+41 x^5+60 x^4+49 x^3+19 x^2+24 x+64$
• $y^2=23 x^6+4 x^5+55 x^4+24 x^3+67 x^2+3 x+62$
• $y^2=19 x^6+28 x^5+30 x^4+26 x^3+43 x^2+21 x+8$
• $y^2=53 x^6+14 x^5+61 x^4+12 x^3+46 x^2+25 x+56$
• $y^2=42 x^6+53 x^5+36 x^4+8 x^3+34 x^2+51 x+2$
• $y^2=52 x^6+7 x^5+2 x^4+38 x^3+39 x^2+65 x+17$
• $y^2=35 x^6+30 x^5+6 x^4+39 x^3+51 x^2+62 x+6$
• $y^2=32 x^6+68 x^5+42 x^4+60 x^3+2 x^2+8 x+42$
• $y^2=28 x^6+66 x^5+66 x^4+33 x^3+23 x^2+19 x+67$
• $y^2=59 x^6+62 x^5+49 x^4+65 x^3+62 x^2+29 x+42$
• $y^2=26 x^6+16 x^5+44 x^4+56 x^3+34 x^2+16 x$
• $y^2=22 x^6+63 x^5+31 x^4+2 x^3+27 x^2+23 x+42$
• $y^2=12 x^6+15 x^5+4 x^4+14 x^3+47 x^2+19 x+10$
• $y^2=37 x^6+25 x^5+52 x^4+52 x^3+36 x^2+41 x+68$
• $y^2=46 x^6+33 x^5+9 x^4+9 x^3+39 x^2+3 x+50$
• $y^2=24 x^6+60 x^5+62 x^4+12 x^3+43 x^2+21 x+70$
• $y^2=26 x^6+65 x^5+8 x^4+13 x^3+17 x^2+5 x+64$
• $y^2=16 x^6+50 x^5+70 x^4+49 x^3+6 x^2+54 x+36$

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{71^{2}}$.

Endomorphism algebra over $\F_{71}$

The isogeny class factors as 1.71.ae $\times$ 1.71.e and its endomorphism algebra is a direct product of the endomorphism algebras for each isotypic factor. The endomorphism algebra for each factor is:

• 1.71.ae : \(\Q(\sqrt{-67}) \).
• 1.71.e : \(\Q(\sqrt{-67}) \).

Endomorphism algebra over $\overline{\F}_{71}$

The base change of $A$ to $\F_{71^{2}}$ is 1.5041.ew^2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-67}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

Twist	Extension degree	Common base change
2.71.ai_gc	$2$	(not in LMFDB)
2.71.i_gc	$2$	(not in LMFDB)
2.71.a_aew	$4$	(not in LMFDB)