Following light cone quantisation of the bosonic string, in the last post we briefly reviewed the free open string spectrum. Now let's take a look at the closed string spectrum.

I thought I would experiment with a new type of weekly post. The premise is simple: I collect and describe some of the papers that I have read that are my favourite or that standout for whatever reason...

And as we'll see in the chapter on stringy CFTs, the Virasoro algebra can be written below, where it acquires a central extension or conformal anomaly...

Now that we understand how to quantise the string, we can summarise by way of Polchinski the construction of the Hilbert space of single string states.

The 'drum-roll moment' is that, in order to regularise this sum, we should invoke the Riemann zeta function. In using $\zeta$-function regularisation, we first consider the general sum...

We now look to the LC quantisation of the string. The first thing to note is that the commutation relation translates on the coefficients of the Fourier mode expansion...

It follows that we now want to turn our focus to quantising the string. Following Polchinski, we shall first take the approach of light-cone quantisation (LCQ)...

when we do the Fourier mode expansion for the wave equation, the function must vanish at both ends of the string. So we must expand in terms of cosine's...

Privacy & Cookies: This site uses cookies. By continuing to use this website, you agree to their use.
To find out more, including how to control cookies, see here: AcceptRead More