nLab principal symbol

Idea

A principal symbol is the highest homogeneous degree part of a symbol of a pseudodifferential operator. Some authors call a principal symbol a “symbol”, and symbol the “total symbol”.

References

• wikipedia
• Y. Kordyukov, F. Sukochev, D. Zanin, $C^\ast$-algebraic approach to the principal symbol. III, arXiv:2309.04500