Open Access
Table 1
Summary of scientific notation.
| Symbol | Meaning |
|---|---|
| 𝒩(μ, Σ) | Normal distribution with mean μ, covariance Σ |
| 𝔼[X] | Expectation value of X |
| cov(X, Y) | Covariance between X and Y |
| x | Column vector of input variable values |
| f | Column vector of function values at input |
| d | Column vector of observed data |
| n | Column vector of noise |
| θ | Set of hyperparameters |
| K | Covariance matrix |
| σ2 | Variance of GP covariance |
| ℓ | Lengthscale of GP covariance |
| ⊗ | Kronecker product |
| IN | Identity matrix (N × N) |
| JN | All-ones matrix (N × N) |
| 1N | Column vector of ones (N × 1) |
| k | Radial Fourier mode |
| k∥ | Line-of-sight Fourier mode |
| k⊥ | Transverse Fourier mode |
| Δ2 | Dimensionless power spectrum |
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