TY - BOOK

T1 - Probing the small distance structure of canonical

AU - t Hooft, G.

N1 - ITP-UU-10/30 - SPIN-10/25

PY - 2010

Y1 - 2010

N2 - In canonical quantum gravity, the formal functional integral includes an integration
over the local conformal factor, and we propose to perform the functional
integral over this factor before doing any of the other functional integrals. By
construction, the resulting effective theory would be expected to be conformally invariant
and therefore finite. However, also the conformal integral itself diverges, and
the effects of a renormalization counter term are considered. It generates problems
such as unitarity violation, due to a Landau-like ghost, and conformal anomalies.
Adding (massive or massless) matter fields does not change the picture. Various
alternative ideas are offered, including a more daring speculation, which is that no
counter term should be allowed for at all. This has far-reaching and important
consequences, which we discuss. A surprising picture emerges of quantized elementary
particles interacting with a gravitational field, in particular gravitons, which
are “partly classical”. This approach was inspired by a search towards the reconciliation
of Hawking radiation with unitarity and locality, and it offers basic new
insights there.

AB - In canonical quantum gravity, the formal functional integral includes an integration
over the local conformal factor, and we propose to perform the functional
integral over this factor before doing any of the other functional integrals. By
construction, the resulting effective theory would be expected to be conformally invariant
and therefore finite. However, also the conformal integral itself diverges, and
the effects of a renormalization counter term are considered. It generates problems
such as unitarity violation, due to a Landau-like ghost, and conformal anomalies.
Adding (massive or massless) matter fields does not change the picture. Various
alternative ideas are offered, including a more daring speculation, which is that no
counter term should be allowed for at all. This has far-reaching and important
consequences, which we discuss. A surprising picture emerges of quantized elementary
particles interacting with a gravitational field, in particular gravitons, which
are “partly classical”. This approach was inspired by a search towards the reconciliation
of Hawking radiation with unitarity and locality, and it offers basic new
insights there.

M3 - Report

BT - Probing the small distance structure of canonical

PB - Spinoza Institute, Utrecht University

ER -