Search Results

Both in Barton Zwiebach's A First Course In String Theory and R. Blumenhagen's Basic Concepts of String Theory, when the Nambu-Goto action $$S_{NG}=\int d^2\sigma \sqrt{-\det(\gamma_{ab})}$$ is presen …

In section 2.2 of David Tong's String Theory lecture notes, he claims that conformal transformations on the flat worldsheet are such that $$\sigma^\pm \to \tilde{\sigma}^\pm(\sigma^\pm).\tag{2.10}$$ I …

When it comes to construct a well-defined path integral for the Polyakov action in Bosonic String Theory, most authors assume that the world sheet metric $g$ is Riemannian (i.e. it has Euclidean signa …

In lecture 10 of this series, the professor defines the notions of speed and length of a curve in a smooth manifold equipped with a metric $g$. These definitions are made between 33:10 and 44:10 and a …

It is commom to define the wordlsheet of a classical open string, for example, as the $2$-dimensional smooth manifold with boundary as $\mathbb{R} \times [0,\pi]$. With the appropriate embedding $X: \ …

I became confused while reading this article for the following reason: For $p=1$ we have strings such that the Nambu-Goto action is proportional to the area of the worldsheet embedded by the maps $X^\ …

In section 2.3 on p. 16 of the book "Basic Concepts of String Theory" by Blumenhagen, Lüst, Theisen, 3 symmetries of Polyakov action are discussed: Poincarè invariance, diffeomorphism invariance and w …

I'm bothered with the motivation behind defining a four-velocity. In Schutz's A First Course in General Relativity, he uses the concept of a tangent vector at each point of a worldline of a particle g …