Quadrature Domain Solver

Domain type

Classical QD
Log-weighted QD (LQD)
Log-weighted QD: ∫Ω f(w)/|w|² dA = ∮∂Ω f·h dw. Non-singular only: requires 0 ∉ Ω̄, so w₀ = φ(0) must be nonzero.
Singular log-weighted QD: 0 ∈ Ω; test functions f ∈ L¹a(Ω; ρ₀) automatically vanish at 0. Riemann map factors as φ(z) = γ · bz₀(z) · exp(r#(z)). The pole of h at the origin contributes residue q (complex); q = 0 is the degenerate case with no log-charge.
Unbounded non-singular log-weighted QD: 0 ∉ Ω̄, ∞ ∈ Ω; test functions f ∈ L¹a(Ω; ρ₀) vanish at ∞. Riemann map: φ(z) = c·z · exp(r#(z) − r#(∞)) on 𝔻*, with conformal radius c = φ′(∞). The − r#(∞) subtraction pins the leading coefficient at ∞ to exactly c.
Unbounded singular log-weighted QD: 0 ∈ Ω AND ∞ ∈ Ω; test functions f vanish at BOTH 0 and ∞ (e.g. w/(w−b)k for k ≥ 2, b ∈ K). Riemann map: φ(z) = c·|z₀|·z·bz₀(z) · exp(r#(z) − r#(∞)) with z₀ ∈ 𝔻* the preimage of 0, and q (complex) the residue of h at the origin. q = 0 is the degenerate case with no log-charge.

Residue q at origin

Complex residue of h at the simple pole at w = 0 (the singular pole inside Ω). Dial via text or the |q| / arg(q) sliders.
0.000
0.000π

Quadrature function h(w)

h(w) = Σj Σs=1..mj Cj,s / (w − aj)s. Enter complex values as e.g. 1+2i.
Polynomial part of h(w) = Σl=0..m∞ C∞,l wl. Quadrature nodes at infinity.
(−1 = no polynomial part)

Riemann map center φ(0)

Conformal radius c = φ′(∞)

Unbounded QDs come in a one-parameter family. Sweep this slider to explore it; past the critical c the simply-connected QD ceases to exist (the solver will flag this).
0.500
Text:

Solver settings

Search options (advanced)

Overrides for the aggressiveness preset. Leave a field blank to use the preset's default. Phase checkboxes are enabled by default.
Phases
Multistart budget
Newton & continuation
Deflation
Acceptance
RNG

Status

Idle
running…

Riemann map φ(z)

Alternate solutions searching…

Algebraic Quadrature Domains

AQDs are Ω with weight ρ = |α|² where α = R′ for some rational primitive R. The inverse problem reduces to solving for the rational function R∘φ on 𝔻̄ via (R∘φ)(z) = R(w₀) + r#(z) (Thm 6.4.1), then numerically inverting R to recover φ.
Stage 0: tab scaffolding only. R-input UI and solver land in Stages 1–2.