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Tensor.zeros

Create a tensor with all admissible blocks filled with zeros.

zeros classmethod 

zeros(
    indices: Sequence[Index],
    dtype: dtype = torch.float64,
    itags: Optional[Sequence[str]] = None,
    device: Optional[Union[str, device]] = None,
    requires_grad: bool = False,
) -> Tensor

Create a symmetry-aware tensor with admissible zero-filled blocks.

Parameters:

Name Type Description Default
indices Sequence[Index]

Sequence of Index objects defining the tensor structure

 required
dtype dtype

Data type for the tensor blocks (default: torch.float64)

 float64
itags Sequence[str]

Tags for each index (default: "init" for all)

 None
device str or device

Device to place tensors on (default: current default device)

 None
requires_grad bool

If True, enables gradient tracking for this tensor (default: False)

 False
Notes

Gradient tracking follows PyTorch's default behavior. Set requires_grad=True to enable autograd for this tensor. Use torch.no_grad() context to temporarily disable gradient computation during operations.

MPS (Apple Silicon) doesn't support float64/complex128. If creating on MPS with these dtypes, they will be automatically downgraded to float32/complex64.

For generic symmetry groups (e.g., SU2), intertwiners (intw) are automatically populated with Bridge objects containing default Clebsch-Gordan specifications.

Description

Creates a new tensor with zero-filled blocks for all charge combinations that satisfy conservation rules. The tensor structure is defined by the provided indices.

See Also

Notes

Only admissible blocks (satisfying charge conservation) are created. The number of blocks depends on the index sectors and symmetry group.