Abelian variety isogeny class 2.61.j_fa over $\F_{61}$

• Label: 2.61.j_fa
• Base field: $\F_{61}$
• 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:	$\F_{61}$
Dimension:	$2$
L-polynomial:	$( 1 + x + 61 x^{2} )( 1 + 8 x + 61 x^{2} )$
	$1 + 9 x + 130 x^{2} + 549 x^{3} + 3721 x^{4}$
Frobenius angles:	$\pm0.520391647268$, $\pm0.671149895095$
Angle rank:	$2$ (numerical)
Jacobians:	$78$
Cyclic group of points:	no
Non-cyclic primes:	$3, 7$

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

$r$	$1$	$2$	$3$	$4$	$5$
$A(\F_{q^r})$	$4410$	$14526540$	$51263604000$	$191664098458560$	$713379864061415250$

Point counts of the curve

$r$	$1$	$2$	$3$	$4$	$5$	$6$	$7$	$8$	$9$	$10$
$C(\F_{q^r})$	$71$	$3901$	$225848$	$13842721$	$844640051$	$51520342858$	$3142743365231$	$191707299924961$	$11694145996193528$	$713342914058740501$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 78 curves (of which all are hyperelliptic):

• $y^2=22 x^6+9 x^5+12 x^4+41 x^3+29 x^2+5 x+10$
• $y^2=45 x^6+34 x^5+54 x^4+59 x^3+57 x^2+56 x+32$
• $y^2=43 x^6+54 x^5+44 x^4+46 x^3+21 x^2+52 x+6$
• $y^2=52 x^6+58 x^5+40 x^4+x^3+31 x^2+53 x+16$
• $y^2=49 x^6+18 x^5+53 x^4+56 x^3+57 x^2+49 x+34$
• $y^2=7 x^6+51 x^5+56 x^4+51 x^3+58 x^2+5 x+22$
• $y^2=12 x^6+46 x^5+12 x^4+32 x^3+36 x^2+25 x+35$
• $y^2=39 x^6+36 x^5+8 x^4+14 x^3+48 x^2+31 x+60$
• $y^2=42 x^6+57 x^5+51 x^4+43 x^3+60 x^2+39 x+28$
• $y^2=50 x^6+39 x^5+34 x^4+26 x^3+25 x^2+59 x+45$
• $y^2=59 x^6+56 x^5+33 x^4+8 x^3+37 x+10$
• $y^2=13 x^6+45 x^5+17 x^4+48 x^3+16 x^2+24 x+15$
• $y^2=10 x^6+49 x^5+7 x^4+6 x^3+41 x^2+12 x+55$
• $y^2=33 x^6+40 x^5+6 x^4+3 x^3+19 x^2+46 x+1$
• $y^2=30 x^6+47 x^5+50 x^4+47 x^3+49 x^2+44 x+3$
• $y^2=31 x^6+51 x^5+51 x^4+15 x^3+19 x^2+18 x+56$
• $y^2=4 x^6+26 x^5+28 x^4+8 x^3+50 x+59$
• $y^2=56 x^6+48 x^5+20 x^4+41 x^3+47 x^2+2 x+29$
• $y^2=50 x^6+40 x^5+60 x^4+48 x^3+10 x^2+8 x+4$
• $y^2=47 x^6+25 x^5+49 x^4+11 x^3+x^2+36 x+14$
• and

• $y^2=19 x^6+51 x^5+19 x^4+35 x^3+21 x^2+52 x+53$
• $y^2=45 x^6+23 x^5+16 x^4+30 x^3+5 x^2+40 x+20$
• $y^2=15 x^6+39 x^5+7 x^4+22 x^3+31 x^2+28 x+37$
• $y^2=42 x^6+59 x^5+31 x^4+11 x^3+42 x^2+x+16$
• $y^2=20 x^6+41 x^5+32 x^3+57 x^2+34 x+27$
• $y^2=16 x^6+56 x^5+19 x^4+7 x^3+27 x^2+50 x+9$
• $y^2=49 x^6+36 x^4+50 x^3+21 x^2+54 x+6$
• $y^2=46 x^6+4 x^5+29 x^4+51 x^3+26 x^2+32 x+43$
• $y^2=46 x^6+25 x^5+48 x^4+13 x^3+23 x^2+32 x+11$
• $y^2=57 x^6+31 x^5+58 x^4+31 x^3+38 x^2+49 x+5$
• $y^2=50 x^6+31 x^5+23 x^4+21 x^3+38 x^2+59 x+22$
• $y^2=49 x^6+27 x^5+11 x^4+11 x^3+53 x^2+41 x+2$
• $y^2=58 x^6+9 x^5+26 x^4+41 x^3+36 x^2+42 x+5$
• $y^2=51 x^6+43 x^5+14 x^4+29 x^3+9 x^2+47 x+57$
• $y^2=4 x^6+18 x^5+42 x^4+27 x^3+5 x^2+x+12$
• $y^2=3 x^6+23 x^5+28 x^4+43 x^3+x^2+37 x+10$
• $y^2=53 x^6+60 x^5+7 x^4+39 x^3+27 x^2+16 x+49$
• $y^2=46 x^6+59 x^5+55 x^4+27 x^3+37 x^2+59 x+35$
• $y^2=10 x^6+15 x^5+46 x^4+39 x^3+58 x^2+48 x+13$
• $y^2=48 x^6+34 x^5+48 x^3+28 x^2+40 x+42$
• $y^2=49 x^6+16 x^5+50 x^4+13 x^3+50 x^2+11 x+32$
• $y^2=60 x^6+49 x^5+60 x^4+26 x^3+58 x^2+6 x+52$
• $y^2=9 x^6+59 x^5+49 x^4+46 x^3+35 x^2+18 x+37$
• $y^2=12 x^6+59 x^5+34 x^4+28 x^3+17 x^2+6 x+18$
• $y^2=27 x^6+19 x^5+52 x^4+6 x^3+58 x^2+4 x+37$
• $y^2=38 x^6+56 x^5+37 x^4+17 x^3+23 x^2+48 x+60$
• $y^2=12 x^6+16 x^5+58 x^4+47 x^3+50 x^2+47 x+24$
• $y^2=47 x^6+x^5+46 x^4+46 x^3+35 x^2+51 x+32$
• $y^2=35 x^6+46 x^5+34 x^4+15 x^3+23 x^2+19 x+10$
• $y^2=28 x^6+27 x^5+55 x^3+9 x^2+32 x+54$
• $y^2=24 x^6+43 x^5+15 x^4+20 x^3+30 x^2+38 x+13$
• $y^2=49 x^6+54 x^5+14 x^4+9 x^3+18 x^2+6 x+60$
• $y^2=22 x^6+44 x^5+9 x^4+38 x^3+40 x^2+40 x+4$
• $y^2=43 x^6+11 x^5+9 x^4+26 x^3+32 x^2+7 x+59$
• $y^2=38 x^6+36 x^5+9 x^4+27 x^3+5 x^2+56 x+28$
• $y^2=58 x^6+45 x^5+54 x^4+10 x^3+3 x^2+27 x$
• $y^2=2 x^6+33 x^5+2 x^4+16 x^3+26 x^2+24 x+21$
• $y^2=51 x^6+40 x^5+27 x^4+27 x^3+41 x^2+58 x+19$
• $y^2=23 x^6+28 x^5+50 x^4+12 x^3+11 x^2+19 x+4$
• $y^2=2 x^6+5 x^5+40 x^4+41 x^3+24 x^2+27 x+59$
• $y^2=19 x^6+60 x^5+17 x^4+6 x^3+42 x^2+29 x+25$
• $y^2=29 x^6+18 x^5+49 x^4+16 x^3+27 x^2+16 x+6$
• $y^2=39 x^6+42 x^5+14 x^4+20 x^3+29 x^2+5 x+57$
• $y^2=56 x^6+15 x^5+28 x^4+9 x^3+43 x^2+33 x$
• $y^2=44 x^6+47 x^5+27 x^4+16 x^3+46 x^2+17 x+14$
• $y^2=17 x^6+29 x^5+55 x^4+27 x^3+36 x^2+22 x+27$
• $y^2=42 x^6+6 x^5+18 x^4+16 x^3+32 x^2+9 x+48$
• $y^2=34 x^6+44 x^5+35 x^4+52 x^3+39 x^2+18 x+1$
• $y^2=36 x^6+48 x^5+48 x^4+41 x^3+54 x^2+60 x+48$
• $y^2=52 x^6+14 x^5+40 x^4+29 x^3+51 x^2+19 x+37$
• $y^2=22 x^6+19 x^4+4 x^3+40 x^2+36 x$
• $y^2=41 x^6+40 x^5+22 x^4+23 x^3+35 x^2+32 x+42$
• $y^2=42 x^6+54 x^5+4 x^4+42 x^3+54 x^2+18 x+46$
• $y^2=37 x^6+58 x^5+5 x^4+29 x^3+40 x^2+29 x+56$
• $y^2=25 x^6+9 x^5+47 x^4+29 x^3+14 x^2+9 x+23$
• $y^2=60 x^6+57 x^5+5 x^4+28 x^3+22 x^2+25 x+60$
• $y^2=2 x^6+44 x^5+59 x^4+30 x^3+55 x^2+48 x+34$
• $y^2=38 x^6+57 x^5+16 x^4+25 x^3+24 x^2+5 x+49$

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{61}$.

Endomorphism algebra over $\F_{61}$

The isogeny class factors as 1.61.b $\times$ 1.61.i and its endomorphism algebra is a direct product of the endomorphism algebras for each isotypic factor. The endomorphism algebra for each factor is:

• 1.61.b : \(\Q(\sqrt{-3}) \).
• 1.61.i : \(\Q(\sqrt{-5}) \).

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
2.61.aj_fa	$2$	(not in LMFDB)
2.61.ah_ek	$2$	(not in LMFDB)
2.61.h_ek	$2$	(not in LMFDB)
2.61.ag_k	$3$	(not in LMFDB)
2.61.v_is	$3$	(not in LMFDB)