We show that the critical behavior of the string tension and most other important qualitative properties of strings are driven by a term in the action containing extrinsic curvatures, which is necessary to add to the Nambu-Goto term. Depending on the renormalization-group structure, strings can be "creased" (with non-zero surface tension at the critical point) or "smooth". Candidates for both possibilities and their physical relevance are discussed.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics