Recent Results in Euclidean Dynamical Triangulations

Abstract

We study a formulation of lattice gravity defined via Euclidean dynamical triangulations (EDT). After fine-tuning a non-trivial local measure term we find evidence that four-dimensional, semi-classical geometries are recovered at long distance scales in the continuum limit. Furthermore, we find that the spectral dimension at short distance scales is consistent with 3/2, a value that is also observed in the causal dynamical triangulation (CDT) approach to quantum gravity.

Quantum gravity phenomenology at the dawn of the multi-messenger era -- A review

“…The second is the Higgs sector of the SM: From a Higgs mass of 125 GeV one can calculate the expected energy dependence of the coupling parameter of the Higgs-particle self-interaction which actually exhibits very nearly scale invariance close to Planckian energies [10,11]. These promising hints contribute to motivating extensive theoretical studies of the asymptotic-safety paradigm for matter-gravity systems with a set of different QFT techniques: functional renormalization group techniques [12,13], lattice techniques [14,15], cf. also Sec.…”

“…For LIV = 0, there would be some high values of E + , E − (and correspondingly E γ ) for which a real θ could solve (15). It must be noticed that the energies needed for this are ultra-high but below-Planckian: photon decay starts to be allowed already at scales roughly of order (m 2 −1 LIV ) 1/3 (which indeed, for m the electron mass and −1 LIV roughly of order the Planck scale, is −1…”

“…In [1227] GRB 169625B along with 23 other time delay GRBs measured by [99] were analyzed with a Gaussian process to reconstruct H(z), utilizing a more complicated relation between the intrinsic and the QG time delay, to produce the following bounds: E QG,1 ≥ 0.3×10 15 GeV and E QG,2 ≥ 0.6×10 9 GeV. Their results showed a strong correlation between the parameters describing intrinsic and propagation time-lags pointing to a need of a better model of the intrinsic lags.…”

Cosmological α′-corrections from the functional renormalization group

“…This identifies the relevant deformation Λ as the leading contribution to the low-energy cosmological constant in the string-frame. 12 The size of the quartic correction approaches that of the classical curvature term when…”

“…1 Despite these studies provide strong evidence for the existence of the Reuter fixed point (see [7,8] and references therein), a complete proof is still lacking due to the practical necessity to truncate. To this end, frameworks such as tensor models [9,10] and dynamical triangulations [11][12][13] could provide alternative ways to seek asymptotic safety in quantum gravity [14][15][16][17][18][19][20], thus complementing the FRG and circumventing its limitations.…”