tensor(6.1062e-16, dtype=torch.float64)
  >>> A = torch.randn(3, 2, 2, dtype=torch.float64)
  >>> A = A + A.mT  # creates a batch of symmetric matrices
  >>> L, Q = torch.linalg.eigh(A)
  >>> torch.dist(Q @ torch.diag_embed(L) @ Q.mH, A)
  tensor(1.5423e-15, dtype=torch.float64)
