Hi,(adsbygoogle = window.adsbygoogle || []).push({});

I am a bit confused about the terminology used for the boundary conditions describing open and closed strings.

For the open string,

Ramond case: [itex]\psi^+(\sigma = \pi, t) = \psi^-(\sigma = \pi, t)[/itex]

Neveu-Schwarz case: [itex]\psi^+(\sigma = \pi, t) = -\psi^-(\sigma = \pi, t)[/itex]

Question 1: Is it correct that the "R sector" refers to the Ramond case, and the "NS sector" refers to the Neveu-Schwarz case?

For the closed string,

Ramond case: [itex]\psi^+(\sigma = 0) = \psi^+(\sigma = \pi)[/itex], [itex]\psi^+(\sigma = 0) = \psi^-(\sigma = \pi)[/itex]

Neveu-Schwarz case: [itex]\psi^+(\sigma = 0) = \psi^+(\sigma = \pi)[/itex], [itex]\psi^+(\sigma = 0) = -\psi^-(\sigma = \pi)[/itex]

Question 2: So,

NS-NS means both [itex]\psi^+[/itex] and [itex]\psi^-[/itex] are antiperiodic

NS-R means [itex]\psi^+[/itex] is antiperiodic and [itex]\psi^-[/itex] is periodic

R-NS means [itex]\psi^-[/itex] is antiperiodic and [itex]\psi^+[/itex] is periodic

R-R means [itex]\psi^+[/itex] is periodic and [itex]\psi^-[/itex] is periodic?

I apologize for the triviality of these questions but the classification of the 4 sectors is confusing me a little...

I'd appreciate some help.

**Physics Forums - The Fusion of Science and Community**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Boundary conditions for open and closed strings

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

Loading...

Similar Threads - Boundary conditions open | Date |
---|---|

Boundary of a spinfoam | Apr 29, 2015 |

Boundary conditions of non relativistic strings | Dec 3, 2014 |

What are strings with endpoint boundary conditions NN, DD, ND and DN? | Nov 25, 2011 |

Boundary conditions in String Theory | May 27, 2010 |

Boundary conditions on D-Branes | Feb 23, 2010 |

**Physics Forums - The Fusion of Science and Community**