标题： 折叠字符串 显示英文标题

标题： Folded Strings

摘要： 近期对二维经典弦理论在任意弯曲时空中的完整解集的研究进展进行了回顾。 当曲率为平滑时，与已知长达19年的平坦时空折叠弦相比，弦解表现为变形的折叠弦解。 然而，在奇点（如黑洞）处，令人惊讶的新弦行为变得明显。 这些解的整体性质要求将黑洞的“裸奇点区域”连同通常的黑洞时空一起包含进去。 描述这些解所需的数学结构包括一个类似于晶格理论传递矩阵的递归关系。 这在一方面编码了世界面上的晶格性质，另一方面编码了时空的几何性质。 文章还提出，在非临界弦的量子理论中存在折叠弦，适用于$d\geq 2$。 显示英文摘要

摘要： Recent progress on the complete set of solutions of two dimensional classical string theory in any curved spacetime is reviewed. When the curvature is smooth the string solutions are deformed folded string solutions as compared to flat spacetime folded strings that were known for 19 years. However, surprizing new stringy behavior becomes evident at singularities such as black holes. The global properties of these solutions require that the ``bare singularity region"of the black hole be included along with the usual black hole spacetime. The mathematical structure needed to describe the solutions include a recursion relation that is analogous to the transfer matrix of lattice theories. This encodes lattice properties on the worldsheet on the one hand and the geometry of spacetime on the other hand. A case is made for the presence of folded strings in the quantum theory of non-critical strings for $d\geq 2$.