Dilaton

In Kaluza–Klein theories, after dimensional reduction, the effective Planck mass varies as some power of the volume of compactified space.

The exponential of its vacuum expectation value determines the coupling constant g and the Euler characteristic   χ = 2 − 2g   as

In supersymmetry the superpartner of the dilaton or here the dilatino, combines with the axion to form a complex scalar field.

However, it has become central to the lower-dimensional many-bodied gravity problem[2] based on the field theoretic approach of Roman Jackiw.

The impetus arose from the fact that complete analytical solutions for the metric of a covariant N-body system have proven elusive in general relativity.

This outcome revealed a previously unknown and already existing natural link between general relativity and quantum mechanics.

However, a recent derivation in 3 + 1 dimensions under the right coordinate conditions yields a formulation similar to the earlier 1 + 1, a dilaton field governed by the logarithmic Schrödinger equation[5] that is seen in condensed matter physics and superfluids.

The field equations are amenable to such a generalization, as shown with the inclusion of a one-graviton process,[6] and yield the correct Newtonian limit in d dimensions, but only with a dilaton.