nLab string theory inspired model




physics, mathematical physics, philosophy of physics

Surveys, textbooks and lecture notes

theory (physics), model (physics)

experiment, measurement, computable physics

String theory



Many models discussed in theoretical physics use ideas which are inspired from phenomena seen in string theory – such as the presence of branes – but handling these loosely, without the (immediate) ambition of validating whether the effects considered really do arise as a string theory vacuum, hence without validating all the constraints that this brings with it, such as quantum anomaly cancellation or even just equations of motion.

Thus one speaks of string inspired models, for instance of string inspired cosmology (e.g. Wands 02, see below).

Vaguely synonymous to string inspired model building is bottom-up model building in string theory, which alludes to the same idea of first loosely arranging ingredients for a given purpose of model building, and only later (if ever) climbing up and checking if and how this arrangement is consistent as a string theory vacuum.

The abundance of string-inspired bottom-up models over accurate top-down model building reflects the strong constraints imposed by string theory on its string vacua, which makes it much harder to construct exact examples even of perturbative string theory vacua than it is to construct vacua in quantum field theory.

An ironic sociological side effect is that the relaxed attitude towards string model building in much of the informal literature leads the lay audience to the perception that it is the theory which is unconstrained instead of its model builders being unrestrained. See also at no-go theorem.


In cosmology

Examples of string-inspired scenarios in cosmology include


  • David Wands, String-inspired cosmology, Class.Quant.Grav. 19 (2002) 3403-3416 (arXiv:hep-th/0203107)

Last revised on May 12, 2019 at 11:59:36. See the history of this page for a list of all contributions to it.