论文标题
关于null字符串的应力能量张量和变异原理的注释
A Note on Stress-Energy Tensor and Variational Principle for Null Strings
论文作者
论文摘要
由于字符串的世界表是堕落的，因此对零字符串的变分原理的直接应用遇到了困难。众所周知，在这种情况下，可以借助于扮演拉格朗日乘数角色的字符串世界表上的两矢量密度来形成各种原理。结果表明，最近建议的零字符串应力 - 能量张量可以通过用于描述字符串理论中无张力极限的动作的背景度量的变化来得出。 Lagrange乘数之一与空字符串的能量有关。
A straightforward application of the variational principle to null strings meets difficulties since string's world-sheets are degenerate. It is known that the variational principle in this case can be formulted with the help of two-vector density on the string world-sheet which plays a role of Lagrange multipliers. It is shown that recently suggested stress-energy tensor of null strings can be derived by variation over the background metric of the action used to describe tensionless limit in the string theory. One of the Lagrange multipliers is related to the energy of the null string.
