The Embedding Model of Induced Gravity with Bosonic Sources

TL;DR

This paper develops a model where spacetime is an embedded surface in higher dimensions, deriving an effective action that includes gravity and matter sources from a quantized embedding framework.

Contribution

It introduces a novel embedding-based approach to induce gravity and matter sources, including p-branes, from a quantized surface in higher-dimensional space.

Findings

Effective action contains Ricci scalar and higher curvature terms.

Source terms corresponding to p-branes are generated.

The model links embedding variables to gravitational and matter dynamics.

Abstract

We consider a theory in which spacetime is an n-dimensional surface $V_n$ embedded in an $N$-dimensional space $V_N$. In order to enable also the Kaluza-Klein approach we admit $n > 4$. The dynamics is given by the minimal surface action in a curved embedding space. The latter is taken, in our specific model, as being a conformally flat space. In the quantization of the model we start from a generalization of the Howe-Tucker action which depends on the embedding variables ${\eta}^a (x)$ and the (intrinsic) induced metric $g_{\mu \nu}$ on $V_n$. If in the path integral we perform only the functional integration over ${\eta}^a (x)$, we obtain the effective action which functionally depends on $g_{\mu \nu}$ and contains the Ricci scalar $R$ and its higher orders $R^2$ etc. But due to our special choice of the conformal factor in $V_N$ enterig our original action, it turns out that the effective action contains also the source term. The latter is in general that of a $p$-dimensional membrane ($p$-brane); in particular we consider the case of a point particle. Thus, starting from the basic fields ${\eta}^a (x)$, we induce not only the kinetic term for $g_{\mu \nu}$, but also the "matter" source term.