Read the equation
The body subtracts its assigned lower estimate from its assigned upper estimate. Their displayed definitions give an η coefficient of 2.618, whereas this comment prints 3.236η. The program’s subtraction follows the endpoints, but neither endpoint is established as the actual matrix extremum by this summary routine.
Terms & definitions
| Term | Meaning in this source |
|---|---|
| W | Difference of assigned spectral endpoints |
| eta | Neighbor-coupling coefficient |
How it works
Read the definition from its right-hand expression to the quantity on the left. Its surrounding source records the intended input, state, or parameter context. Where the source leaves an operation unspecified, this page preserves that gap.
Assumptions & limits
Source recovery establishes that the expression appears in this record. Its mathematical validity, implementation behavior, and interpretation must be assessed separately. See the linked source and research notes for the checks available for this version.
Original context
Read the surrounding source passage
// λ₂₂ = 0 (zero mode, Goldstone)
s.lambda_22 = 0.0;
// λ₄₄ = κ + 1.2β₀ + γ + 2.618η (highest, bonding)
s.lambda_44 = params_.kappa_intra + 1.2 * params_.beta_0 +
params_.gamma + 2.618 * params_.eta;
// W = λ₄₄ - λ₁ = 4α + 2κ + 1.2β₀ + 2γ + γ₀ + 3.236η
s.spectral_width = s.lambda_44 - s.lambda_1;
return s;
}
// Approximate spectrum using block eigenvalues
std::vector<double> approximate_spectrum() const {
std::vector<double> spectrum;
spectrum.reserve(TOTAL_BONDS);
Exact original notation
W = λ₄₄ - λ₁ = 4α + 2κ + 1.2β₀ + 2γ + γ₀ + 3.236η