This document discusses Darmon points for fields of mixed signature. It begins by reviewing some history on constructing Darmon points when the field is not totally complex. It then outlines goals to sketch a general construction of Darmon points, give details of the construction, explain algorithmic challenges, and illustrate with examples. Notation is introduced for places that split or ramify when extending a number field. The talk will focus on constructing non-archimedean Darmon points.
Darmon points for fields of mixed signature seminar
1. Darmon points for fields of mixed signature
Number Theory Seminar, University of Warwick
Xavier Guitart 1 Marc Masdeu 2 Mehmet Haluk Sengun 3
1Institut f¨ur Experimentelle Mathematik
2,3University of Warwick
January 27, 2014
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 0 / 1
2. The Hasse-Weil L-function
Let F be a number field.
Let E/F be an elliptic curve of conductor N = NE.
Let K/F be a quadratic extension of F.
Assume for simplicity that N is square-free, coprime to disc(K/F).
Hasse-Weil L-function of the base change of E to K ( (s) >> 0)
L(E/K, s) =
p|N
1 − ap|p|−s −1
×
p N
1
ap(E) = 1 + |p| − #E(Fp).
− ap|p|−s
+ |p|1−2s −1
.
Assume Modularity conjecture (see Samir’s talk in 4 weeks) =⇒
Analytic continuation of L(E/K, s) to C.
Functional equation relating s ↔ 2 − s.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 1 / 1
3. The BSD conjecture
Brian Birch Sir Peter Swinnerton-Dyer
Coarse version of BSD conjecture
ords=1 L(E/K, s) = rkZ E(K).
So L(E/K, 1) = 0
BSD
=⇒ ∃PK ∈ E(K) of infinite order.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 2 / 1
4. The main tool for BSD: Heegner points
Kurt Heegner
Exist for F totally real and K/F totally complex (CM extension).
I recall the definition of Heegner points in the simplest setting:
F = Q (and K/Q imaginary quadratic), and
Heegner hypothesis: | N =⇒ split in K.
This ensures that ords=1 L(E/K, s) is odd (so ≥ 1).
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 3 / 1
5. Heegner Points (K/Q imaginary quadratic)
Attach to E a holomorphic 1-form on H = {z ∈ C : (z) > 0}.
ΦE = fE(z)dz =
n≥1
ane2πinz
dz ∈ H0
(Γ0(N)
Γ0(N) = { a b
c d ∈ SL2(Z): N | c}
, Ω1
H).
Given τ ∈ K ∩ H, set Jτ =
τ
∞
ΦE ∈ C.
Well-defined up to the lattice ΛE = γ ΦE | γ ∈ H1 Γ0(N)H, Z .
There exists an isogeny η: C/ΛE → E(C).
Set Pτ = η(Jτ ) ∈ E(C).
Fact: Pτ ∈ E(Hτ ), where Hτ /K is a class field attached to τ.
Theorem (Gross-Zagier)
PK = TrHτ /K(Pτ ) nontorsion ⇐⇒ L (E/K, 1) = 0.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 4 / 1
6. Heegner Points: revealing the trick
So why does this work?
1 The Riemann surface Γ0(N)H has an algebraic model X0(N)/Q.
2 There is a morphism φ defined over Q:
φ: Jac(X0(N)) → E.
3 The CM point (τ) − (∞) ∈ Jac(X0(N)) gets mapped to:
φ((τ) − (∞)) = Pτ ∈ E(Hτ ).
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 5 / 1
7. Computing in practice: an example of Mark Watkins
Let E be the elliptic curve of conductor NE = 66157667:
E : y2
+ y = x3
− 5115523309x − 140826120488927.
Watkins worked with 460 digits of precision and 600M terms of the
L-series. Took less than a day (in 2006). The x-coordinate of the point
has numerator:
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Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 6 / 1
8. Darmon’s insight
Henri Darmon
Drop hypothesis of K/F being CM.
Simplest case: F = Q, K real quadratic.
However:
There are no points on Jac(X0(N)) attached to such K.
In general there is no morphism φ: Jac(X0(N)) → E.
When F is not totally real, even the curve X0(N) is missing!
Nevertheless, Darmon constructed local points in such cases. . .
. . . and hoped that they were global.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 7 / 1
9. Goals of this talk
1 Review some history.
2 Sketch a general construction of Darmon points.
3 Give some details of the construction.
4 Explain the algorithmic challenges we face in their computation.
“The fun of the subject seems to me to be in the examples.
B. Gross, in a letter to B. Birch, 1982
”5 Illustrate with fun examples.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 8 / 1
10. Basic notation
Consider an infinite place v | ∞F of F.
If v is real, then:
1 It may extend to two real places of K (splits), or
2 It may extend to one complex place of K (ramifies).
If v is complex, then it extends to two complex places of K (splits).
n = #{v | ∞F : v splits in K}.
K/F is CM ⇐⇒ n = 0.
If n = 1 we call K/F quasi-CM.
S(E, K) = v | N∞F : v not split in K , s = #S(E, K).
Sign of functional equation for L(E/K, s) should be (−1)#S(E,K).
From now on, we assume that s is odd.
Fix a place ν ∈ S(E, K).
1 If ν = p is finite =⇒ non-archimedean case.
2 If ν is infinite =⇒ archimedean case.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 9 / 1
11. Goals of this talk
1 Review some history.
2 Sketch a general construction of Darmon points.
3 Give some details of the construction.
4 Explain the algorithmic challenges we face in their computation.
“The fun of the subject seems to me to be in the examples.
B. Gross, in a letter to B. Birch, 1982
”5 Illustrate with fun examples.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 10 / 1
12. Non-archimedean History
These constructions are also known as Stark-Heegner points.
H. Darmon (1999): F = Q, quasi-CM, s = 1.
Darmon-Green (2001): special cases, used Riemann products.
Darmon-Pollack (2002): same cases, overconvergent methods.
Guitart-M. (2012): all cases, overconvergent methods.
M. Trifkovic (2006): F imag. quadratic ( =⇒ quasi-CM)), s = 1.
Trifkovic (2006): F euclidean, E of prime conductor.
Guitart-M. (2013): F arbitrary, E arbitrary.
M. Greenberg (2008): F totally real, arbitrary ramification, s ≥ 1.
Guitart-M. (2013): F = Q, quasi-CM case, s ≥ 1.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 11 / 1
13. Archimedean History
Initially called Almost Totally Real (ATR) points.
But this name only makes sense in the original setting of Darmon.
H. Darmon (2000): F totally real, s = 1.
Darmon-Logan (2003): F quadratic norm-euclidean, NE trivial.
Guitart-M. (2011): F quadratic and arbitrary, NE trivial.
Guitart-M. (2012): F quadratic and arbitrary, NE arbitrary.
J. Gartner (2010): F totally real, s ≥ 1.
?
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 12 / 1
14. Goals of this talk
1 Review some history.
2 Sketch a general construction of Darmon points.
3 Give some details of the construction.
4 Explain the algorithmic challenges we face in their computation.
“The fun of the subject seems to me to be in the examples.
B. Gross, in a letter to B. Birch, 1982
”5 Illustrate with fun examples.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 13 / 1
15. Our construction
Xavier Guitart M. Haluk Sengun
Available for arbitrary base number fields F (mixed signature).
Comes in both archimedean and non-archimedean flavors.
All of the previous constructions become particular cases.
We can provide genuinely new numerical evidence.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 14 / 1
16. Overview of the construction
We define a quaternion algebra B/F and a group Γ ⊂ SL2(Fν).
The group Γ acts (non-discretely in general) on Hν.
We attach to E a unique cohomology class
ΦE ∈ Hn
Γ, Ω1
Hν
.
We attach to each embedding ψ: K → B a homology class
Θψ ∈ Hn Γ, Div0
Hν .
Well defined up to the image of Hn+1(Γ, Z)
δ
→ Hn(Γ, Div0
Hν).
Cap-product and integration on the coefficients yield an element:
Jψ = Θψ, ΦE ∈ K×
ν .
Jψ is well-defined up to a multiplicative lattice
L = δ(θ), ΦE : θ ∈ Hn+1(Γ, Z) .
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 15 / 1
17. Conjectures
Jψ = Θψ, ΦE ∈ K×
ν /L.
Conjecture 1 (Oda, Yoshida, Greenberg, Guitart-M-Sengun)
There is an isogeny β : K×
ν /L → E(Kν).
Proven in some non-arch. cases (Greenberg, Rotger–Longo–Vigni).
Completely open in the archimedean case.
The Darmon point attached to E and ψ: K → B is:
Pψ = β(Jψ) ∈ E(Kν).
Conjecture 2 (Darmon, Greenberg, Trifkovic, Gartner, G-M-S)
1 The local point Pψ is global, and belongs to E(Kab).
2 Pψ is nontorsion if and only if L (E/K, 1) = 0.
We predict also the exact number field over which Pψ is defined.
Include a Shimura reciprocity law like that of Heegner points.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 16 / 1
18. Goals of this talk
1 Review some history.
2 Sketch a general construction of Darmon points.
3 Give some details of the construction.
4 Explain the algorithmic challenges we face in their computation.
“The fun of the subject seems to me to be in the examples.
B. Gross, in a letter to B. Birch, 1982
”5 Illustrate with fun examples.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 17 / 1
19. The group Γ
Let B/F = quaternion algebra with Ram(B) = S(E, K) {ν}.
B = M2(F) (split case) ⇐⇒ s = 1.
Otherwise, we are in the quaternionic case.
E and K determine a certain {ν}-arithmetic subgroup Γ ⊂ SL2(Fν):
Let m = l|N, split in K l.
Let RD
0 (m) be an Eichler order of level m inside B.
Fix an embedding ιν : RD
0 (m) → M2(ZF,ν).
Γ = ιν RD
0 (m)[1/ν]×
1 ⊂ SL2(Fν).
e.g. S(E, K) = {p} and ν = p give Γ ⊆ SL2 OF [1
p ] .
e.g. S(E, K) = {∞} and ν = ∞ give Γ ⊆ SL2 (OF ).
Remark: We also write ΓD
0 (m) = RD
0 (m)×
1 .
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 18 / 1
20. Path integrals: archimedean setting
H = (P1(C) P1(R))+ has a complex-analytic structure.
SL2(R) acts on H through fractional linear transformations:
a b
c d · z =
az + b
cz + d
, z ∈ H.
We consider holomorphic 1-forms ω ∈ Ω1
H.
Given two points P and Q in H, define:
Q
P
ω = usual path integral.
Compatibility with the action of SL2(R) on H:
γQ
γP
ω =
Q
P
γ∗
ω.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 19 / 1
21. Path integrals: non-archimedean setting
Hp = P1(Kp) P1(Fp) has a rigid-analytic structure.
SL2(Fp) acts on Hp through fractional linear transformations:
a b
c d · z =
az + b
cz + d
, z ∈ Hp.
We consider rigid-analytic 1-forms ω ∈ Ω1
Hp
.
Given two points P and Q in Hp, define:
Q
P
ω = Coleman integral.
Compatibility with the action of SL2(Fp) on Hp:
γQ
γP
ω =
Q
P
γ∗
ω.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 20 / 1
22. Coleman Integration
Coleman integration on Hp can be defined as:
τ2
τ1
ω =
P1(Fp)
logp
t − τ2
t − τ1
dµω(t) = lim
−→
U U∈U
logp
tU − τ2
tU − τ1
resA(U)(ω).
Bruhat-Tits tree of GL2(Fp), |p| = 2.
Hp having the Bruhat-Tits as retract.
Annuli A(U) for a covering of size |p|−3.
tU is any point in U ⊂ P1(Fp).
P1(Fp)
U ⊂ P1
(Fp)
If resA(U)(ω) ∈ Z for all U, then have a multiplicative refinement:
×
τ2
τ1
ω = lim
−→
U U∈U
tU − τ2
tU − τ1
resA(U)(ω)
∈ K×
p .
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 21 / 1
23. Cohomology
Recall that S(E, K) and ν determine:
Γ = ιν RD
0 (m)[1/ν]×
1 ⊂ SL2(Fν).
Choose “signs at infinity” s1, . . . , sn ∈ {±1}.
Theorem (Darmon, Greenberg, Trifkovic, Gartner, G.–M.–S.)
There exists a unique (up to sign) class
ΦE ∈ Hn
Γ, Ω1
Hν
such that:
1 TlΦE = alΦE for all l N.
2 UqΦE = aqΦE for all q | N.
3 Wσi ΦE = siΦE for all embeddings σi : F → R which split in K.
4 ΦE is “integrally valued”.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 22 / 1
24. Homology
Let ψ: O → RD
0 (m) be an embedding of an order O of K.
Which is optimal: ψ(O) = RD
0 (m) ∩ ψ(K).
Consider the group O×
1 = {u ∈ O× : NmK/F (u) = 1}.
rank(O×
1 ) = rank(O×
) − rank(O×
F ) = n.
Choose a basis u1, . . . , un ∈ O×
1 for the non-torsion units.
; ∆ψ = ψ(u1) · · · ψ(un) ∈ Hn(Γ, Z).
K× acts on Hν through K× ψ
→ B× ιν
→ GL2(Fν).
Let τψ be the (unique) fixed point of K×
on Hν.
Have the exact sequence
Hn+1(Γ, Z)
δ // Hn(Γ, Div0
Hν) // Hn(Γ, Div Hν)
deg
// Hn(Γ, Z)
Θψ
? // [∆ψ ⊗τψ] // [∆ψ]
Fact: [∆ψ] is torsion.
Can pull back a multiple of [∆ψ ⊗τψ] to Θψ ∈ Hn(Γ, Div0
Hν).
Well defined up to δ(Hn+1(Γ, Z)).
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 23 / 1
25. Goals of this talk
1 Review some history.
2 Sketch a general construction of Darmon points.
3 Give some details of the construction.
4 Explain the algorithmic challenges we face in their computation.
“The fun of the subject seems to me to be in the examples.
B. Gross, in a letter to B. Birch, 1982
”5 Illustrate with fun examples.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 24 / 1
26. Commutator Decomposition
Goal
H2(Γ, Z)
δ // H1(Γ, Div0
Hp) // H1(Γ, Div Hp)
deg
// H1(Γ, Z)
Θψ
? // [γψ ⊗τψ] // [γψ]
Theorem (word problem)
Given a presentation F Γ giving
Γ = g1, . . . , gs | r1, . . . , rt ,
There is an algorithm to write γ ∈ Γ as a word in the gi’s.
Effective version for quaternionic groups: John Voight, Aurel Page.
γ ∈ [Γ, Γ] =⇒ γ has word representation W, with W ∈ [F, F].
We use gh ⊗D ≡ g ⊗D + h ⊗g−1D (as 1-cycles).
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 25 / 1
27. Commutator Decomposition: example
G = R×
1 , R maximal order on B = B6.
F = X, Y G = x, y | x2
= y3
= 1 .
Goal: write g ⊗τ as gi ⊗Di, with Di of degree 0.
Take for instance g = yxyxy. Note that wt(x) = 2 and wt(y) = 3.
First, trivialize on Fab: g = yxyxyx−2y−3.
To simplify γ ⊗τ0 in H1(Γ, Div Hp), use:
1 gh ⊗D ≡ g ⊗D + h ⊗g−1
D.
2 g−1
⊗D ≡ −g ⊗gD.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 26 / 1
28. Overconvergent Method (I) (F = Q, p = fixed prime)
We have attached to E a cohomology class Φ ∈ H1(Γ, Ω1
Hp
).
Goal: to compute integrals
τ2
τ1
Φγ, for γ ∈ Γ.
Recall that τ2
τ1
Φγ =
P1(Qp)
log
t − τ1
t − τ2
dµγ(t).
Expand the integrand into power series and change variables.
We are reduced to calculating the moments:
Zp
ti
dµγ(t) for all γ ∈ Γ.
Note: Γ ⊇ ΓD
0 (m) ⊇ ΓD
0 (pm).
Technical lemma: All these integrals can be recovered from
Zp
ti
dµγ(t): γ ∈ ΓD
0 (pm) .
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 27 / 1
29. Overconvergent Method (II)
D = {locally analytic Zp-valued distributions on Zp}.
ϕ ∈ D maps a locally-analytic function h on Zp to ϕ(h) ∈ Zp.
D is naturally a ΓD
0 (pm)-module.
The map ϕ → ϕ(1Zp ) induces a projection:
ρ: H1
(ΓD
0 (pm), D) → H1
(ΓD
0 (pm), Zp).
Theorem (Pollack-Stevens, Pollack-Pollack)
There exists a unique Up-eigenclass ˜Φ lifting ΦE.
Moreover, ˜Φ is explicitly computable by iterating the Up-operator.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 28 / 1
30. Overconvergent Method (III)
But we wanted to compute the moments of a system of measures. . .
Proposition
Consider the map Ψ: ΓD
0 (pm) → D:
γ → h(t) →
Zp
h(t)dµγ(t) .
1 Ψ belongs to H1(ΓD
0 (pm), D).
2 Ψ is a lift of µ.
3 Ψ is a Up-eigenclass.
Corollary
The explicitly computed ˜Φ knows the above integrals.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 29 / 1
32. Available Code
SAGE code for non-archimedean Darmon points when n = 1.
https://github.com/mmasdeu/darmonpoints
Compute with “quaternionic modular symbols”.
Need presentation for units of orders in B (J. Voight, A. Page).
Implemented overconvergent method for arbitrary B.
We obtain a method to find algebraic points.
SAGE code for archimedean Darmon points (in restricted cases).
https://github.com/mmasdeu/atrpoints
Only for the split (B = M2(F)) cases, and:
1 F real quadratic, and K/F ATR (Hilbert modular forms)
2 F cubic (1, 1), and K/F totally complex (cubic automorphic forms).
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 30 / 1
33. Archimedean cubic Darmon point (I)
Let F = Q(r) with r3 − r2 + 1 = 0.
F has discriminant −23, and is of signature (1, 1).
Consider the elliptic curve E/F given by the equation:
E/F : y2
+ (r − 1) xy + r2
− r y = x3
+ −r2
− 1 x2
+ r2
x.
E has prime conductor NE = r2 + 4 of norm 89.
K = F(w), with w2 + (r + 1) w + 2r2 − 3r + 3 = 0.
K has class number 1, thus we expect the point to be defined over K.
The computer tells us that rkZ E(K) = 1
S(E, K) = {σ}, where σ: F → R is the real embedding of F.
Therefore the quaternion algebra B is just M2(F).
The arithmetic group to consider is
Γ = Γ0(NE) ⊂ SL2(OF ).
Γ acts naturally on the symmetric space H
Hyperbolic 3-space
× H3:
H × H3 = {(z, x, y): z ∈ H, x ∈ C, y ∈ R0}.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 31 / 1
34. Archimedean cubic Darmon point (II)
E ; ωE, an automorphic form with Fourier-Bessel expansion:
ωE(z, x, y) =
α∈δ−1OF
α00
a(δα)(E)e−2πi(α0 ¯z+α1x+α2 ¯x)
yH (α1y) ·
−dx∧d¯z
dy∧d¯z
d¯x∧d¯z
H(t) = −
i
2
eiθ
K1(4πρ), K0(4πρ),
i
2
e−iθ
K1(4πρ) t = ρeiθ
.
K0 and K1 are hyperbolic Bessel functions of the second kind:
K0(x) =
∞
0
e−x cosh(t)
dt, K1(x) =
∞
0
e−x cosh(t)
cosh(t)dt.
ωE is a 2-form on ΓH × H3.
The cocycle ΦE is defined as (γ ∈ Γ):
ΦE(γ) =
γ·O
O
ωE(z, x, y) ∈ Ω1
H with O = (0, 1) ∈ H3.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 32 / 1
35. Archimedean cubic Darmon point (III)
Consider the embedding ψ: K → M2(F) given by:
w →
−2r2 + 3r r − 3
r2 + 4 2r2 − 4r − 1
Let γψ = ψ(u), where u is a fundamental norm-one unit of OK.
γψ fixes τψ = −0.7181328459824 + 0.55312763561813i ∈ H.
Construct Θψ = [γψ ⊗τψ] ∈ H1(Γ, Div H).
Θψ is equivalent to a cycle γi ⊗(si − ri) taking values in Div0
H.
Jψ =
i
si
ri
ΦE(γi) =
i
γi·O
O
si
ri
ωE(z, x, y).
We obtain, summing over all ideals (α) of norm up to 400, 000:
Jψ = 0.0005281284234 + 0.0013607546066i ; Pψ ∈ E(C).
Numerically (up to 32 decimal digits) we obtain:
Pψ
?
= −10 × r − 1, w − r2
+ 2r ∈ E(K).
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 33 / 1
36. Non-archimedean cubic Darmon point (I)
F = Q(r), with r3 − r2 − r + 2 = 0.
F has signature (1, 1) and discriminant −59.
Consider the elliptic curve E/F given by the equation:
E/F : y2
+ (−r − 1) xy + (−r − 1) y = x3
− rx2
+ (−r − 1) x.
E has conductor NE = r2 + 2 = p17q2, where
p17 = −r2
+ 2r + 1 , q2 = (r) .
Consider K = F(α), where α =
√
−3r2 + 9r − 6.
The quaternion algebra B/F has discriminant D = q2:
B = F i, j, k , i2
= −1, j2
= r, ij = −ji = k.
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 34 / 1
37. Non-archimedean cubic Darmon point (II)
The maximal order of K is generated by wK, a root of the polynomial
x2
+ (r + 1)x +
7r2 − r + 10
16
.
One can embed OK in the Eichler order of level p17 by:
wK → (−r2
+ r)i + (−r + 2)j + rk.
We obtain γψ = 6r2−7
2 + 2r+3
2 i + 2r2+3r
2 j + 5r2−7
2 k, and
τψ = (12g+8)+(7g+13)17+(12g+10)172
+(2g+9)173
+(4g+2)174
+· · ·
After integrating we obtain:
Jψ = 16+9·17+15·172
+16·173
+12·174
+2·175
+· · ·+5·1720
+O(1721
),
which corresponds to:
Pψ = −
3
2
× 72 × r − 1,
α + r2 + r
2
∈ E(K).
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 35 / 1
38. Thank you !
Bibliography, code and slides at:
http://www.warwick.ac.uk/mmasdeu/
Marc Masdeu Darmon points for fields of mixed signature January 27, 2014 35 / 1
39. Bibliography
H. Darmon and A. Logan. Periods of Hilbert modular forms and rational points on elliptic curves.
Int. Math. Res. Not. (2003), no. 40, 2153–2180.
H. Darmon and P. Green. Elliptic curves and class fields of real quadratic fields: Algorithms and evidence.
Exp. Math., 11, No. 1, 37-55, 2002.
H. Darmon and R. Pollack. Efficient calculation of Stark-Heegner points via overconvergent modular symbols.
Israel J. Math., 153:319–354, 2006.
J. G¨artner. Darmon points and quaternionic Shimura varieties.
Canad. J. Math. 64 (2012), no. 6.
X. Guitart and M. Masdeu. Elementary matrix Decomposition and the computation of Darmon points with higher conductor.
Math. Comp. (arXiv.org, 1209.4614), 2013.
X. Guitart and M. Masdeu. Computation of ATR Darmon points on non-geometrically modular elliptic curves.
Exp. Math., 2012.
X. Guitart and M. Masdeu. Computation of quaternionic p-adic Darmon points.
(arXiv.org, 1307.2556), 2013.
M. Greenberg. Stark-Heegner points and the cohomology of quaternionic Shimura varieties.
Duke Math. J., 147(3):541–575, 2009.
D. Pollack and R. Pollack. A construction of rigid analytic cohomology classes for congruence subgroups of SL3(Z).
Canad. J. Math., 61(3):674–690, 2009.
M. Trifkovic. Stark-Heegner points on elliptic curves defined over imaginary quadratic fields.
Duke Math. J., 135, No. 3, 415-453, 2006.
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