src/uni20/symmetry

This directory contains quantum-number and block-sparse symmetry infrastructure. These types define which sectors and blocks exist; losing this metadata changes the mathematical problem and is treated as a correctness bug.

Contents

• qnum.hpp: quantum-number value types.
• block_sector.hpp: shared (QNum, dimension) block records.
• space.hpp: common Space and SymmetrySpace concepts.
• dual_space.hpp: generic Dual<S> basis adaptor and DualSpace concept.
• irregular_space.hpp: immutable ordered segmented spaces with repeated sectors.
• local_space.hpp: immutable ordered local-state spaces.
• qnum_space.hpp: single-irrep tensor spaces.
• dense_space.hpp: symmetry-neutral dense tensor spaces.
• morphism_boundary.hpp: ordered Domain<...> and Codomain<...> space values.
• block_key.hpp: opaque logical block coordinates.
• block_tensor_space_traits.hpp: independent block-key-coordinate and dense-axis classification for concrete space kinds.
• block_tensor_storage.hpp: serial and scheduler-batched separate and packed storage, generalized-diagonal storage, and per-block async storage.
• block_tensor_concepts.hpp: common readable, mutable, immediate, borrowed, and async BlockTensor view vocabulary.
• block_tensor.hpp: the first order-zero through order-four BlockTensor slice for LocalSpace, QNumSpace, BlockSpace, and explicit dual boundaries.
• block_tensor_mapped_view.hpp: owned logical-to-physical key and dense-axis descriptor metadata for composable zero-copy borrowed views.
• block_tensor_permute.hpp: zero-copy bosonic permutations within domain and codomain.
• block_tensor_repartition.hpp: zero-copy bosonic left/right wire-bending views with transformed logical keys and strided dense blocks.
• block_tensor_linear.hpp: structure-preserving copy, zero, scaling, addition, AXPY, inner-product, and norm operations.
• block_tensor_svd.hpp: staged host block SVD with globally selected charge-labelled states and repeatable factor/null-space materialization.
• block_tensor_contract.hpp: returning and fixed-output adjacent pairwise sparse contraction over exact codomain/domain space values.
• symmetry.hpp, symmetryimpl.hpp, symmetryfactor.hpp: symmetry declarations, implementations, and factor helpers.
• u1.hpp: U(1) symmetry support.
• block_space.hpp: immutable coalesced block spaces and explicit local-to-block regularization.

Notes

• Symmetry-aware tensor paths must preserve quantum-number, block, and leg orientation metadata.
• Dense projections are allowed only as explicitly named diagnostics or reference conversions. They must not silently feed back into a symmetry-aware computation.

Related Documentation

• Source tree map
• Symmetry and block-sparse documentation
• Quantum numbers and symmetry
• Raw primitives and symmetric lowering