tom.stoer

Science Advisor

- 5,759

- 159

## Main Question or Discussion Point

I try to read all relevant papers regarding LQG, but of course for an outsider this is no longer not possible, therefore somehow I lost track when it comes to certain special topics.

Some years ago authors like Smolin wrote review articles regarding current status, open issues and research topics. In addition there where of course the two books by Rovelli and Thiemann which provided an excellent introduction and a a thorough exposition of the formalism.

This is something I am missing today.

Rovelli has written some overview articles, e.g. his "Zakopane lectures", but these are not very exhaustive. For special topics there are no review articles available, especially articles already taking into account the spin foam formalism.

So my question is whether there is a recent review article (or a new book in preparation) covering (some of) the following topics including relevant open issues:

- definition and status of path integral and canonical formalism plus their relation

- open (or solved) issues regarding Hamiltonian, dynamics, regularization, off-shell closure of constraint algebra, ...

- meaning, value, ... of the Immirzi parameter

- different classes of spin networks, different vertices / intertwiners (higher SU(N) and/or higher dimension)

- different graphes w/ and w/o dual triangulation

- quantum deformation, status of the cosmological constant

- matter coupling for fermions and gauge fields, gauge fixing for other gauge fields, SUSY / SUGRA

- renormalization, summing / refining, "block-spin" method

- horizons, surface Hilbert spaces, holographic principle

- definition of observables

- construction of coherent states, semiclassical limit, propagators, ...

- phenomenology

Some years ago authors like Smolin wrote review articles regarding current status, open issues and research topics. In addition there where of course the two books by Rovelli and Thiemann which provided an excellent introduction and a a thorough exposition of the formalism.

This is something I am missing today.

Rovelli has written some overview articles, e.g. his "Zakopane lectures", but these are not very exhaustive. For special topics there are no review articles available, especially articles already taking into account the spin foam formalism.

So my question is whether there is a recent review article (or a new book in preparation) covering (some of) the following topics including relevant open issues:

- definition and status of path integral and canonical formalism plus their relation

- open (or solved) issues regarding Hamiltonian, dynamics, regularization, off-shell closure of constraint algebra, ...

- meaning, value, ... of the Immirzi parameter

- different classes of spin networks, different vertices / intertwiners (higher SU(N) and/or higher dimension)

- different graphes w/ and w/o dual triangulation

- quantum deformation, status of the cosmological constant

- matter coupling for fermions and gauge fields, gauge fixing for other gauge fields, SUSY / SUGRA

- renormalization, summing / refining, "block-spin" method

- horizons, surface Hilbert spaces, holographic principle

- definition of observables

- construction of coherent states, semiclassical limit, propagators, ...

- phenomenology