User Guide

Detailed coverage of every feature in sft-wick, organised by topic.

Getting productive (L1)

• Workflow API (L1 + L2)
  • Which layer to use
  • Quick start — L2 (config file)
  • Quick start — L1 (Python)
  • The five headline types
  • MSR convention — the one gotcha
  • Observable convention — integrate_over
  • Time-dependent linear operator
  • Dynamic coupling (spacetime-dependent κ^(m))
  • d-dim spatial coordinates
  • YAML configuration reference (L2)
  • Homogeneity modes
• Time discretization (dt)
  • What dt means
  • Example
  • When to use kappa2 vs sigma2
  • Choosing dt
  • Convergence
  • Parallelism layers
• Parallelism (n_jobs)
  • The four parallelism layers
  • Choosing where to parallelise
  • Mutual exclusion (no nested pools)
  • BLAS thread oversubscription

Building blocks (L0)

• Fields and Field Operators
  • Field Types
  • Creating Fields
  • Creating Field Operators
  • UID System and Test Reproducibility
  • Field Operator Properties
• Interaction Vertices and Actions
  • Defining a Vertex
  • Building an Action
  • Multinomial Expansion
  • Vertex Instantiation
• Computing Perturbative Expansions
  • Basic Usage
  • The PerturbativeResult Object
  • Accessing Individual Orders
  • What Happens Internally
  • Sign and Factorial
  • Itô Prescription and Causality
  • Response Phase Convention
  • Diagram-Based Term Collection
  • Zeroth-Order Calculations
• The Expression Tree
  • Design Philosophy
  • The Expr Base Class
  • Numeric: Rational
  • Symbolic: Symbol
  • Propagators
  • Composite: Sum and Product
  • Wrappers: SumOverIndex and IntegralOver
  • Delta Functions
  • Immutability and Hashability
  • Imaginary Unit: ImaginaryUnit
• Expression Simplification
  • The Pipeline
  • Term Signatures
  • Diagram-Based Collection
  • When Simplification Runs
• Feynman Diagrams
  • The FeynmanDiagram Class
  • Building Diagrams
  • Topological Properties
  • Rendering with DiagramRenderer
  • Quick Visualisation
  • Visual Conventions
  • Layout Algorithm
  • Customising the Appearance
  • TikZ/PGF Backend
• LaTeX Output
  • The to_latex() Method
  • Custom Propagator Names
  • Equation Formatting
  • Aligned Environment
  • Integrating into Papers