TH Theoretical Seminar

# Quantum Gravity - Important Challenge for Theoretical Physics

## by Jerzy Lukierski

Wednesday, 13 November 2013 from to (Europe/Zurich)
at CERN ( 4-3-006 - TH Conference Room )
 Description After short historical introduction about the description of fundamental interactions I shall recall the nonrenormalizability of quantum gravity (QG) in perturbative QFT approach. It will be pointed out the difference between the notion of space-time fields in particle physics and in quantum gravity taking into consideration the dynamical nature of space-time. In particular it will be pointed out the appearance of noncommutative space-times as characteristic feature of QG at Planck distances. Further we shall consider briefly four main approaches to QG: a) Loop quantum gravity, b) QG as deformed field theory on noncommutative space-time, c) Functional formulation of QG and lattice approach, d) QG as a sector of quantized string field theory. We argue that these approaches are rather complementary in formulating of QG model with desired properties (covariance under local diffeomorphisms, background space- time field independence, appearance of noncommutative space-times at ultrashort distances, finiteness of calculated QG effects, incorporation of QG into unified model of fundamental interactions).