activity
20242026
collaborators

13 papers

hep-th2026

The perturbative Ricci flow in gravity

Robert V. Harlander, Yannick Kluth, Jonas T. Kohnen +1

We develop a perturbative formulation of the Ricci flow in gravity. Following steps analogous to the gradient flow in QCD, we supplement the usual Feynman rules for perturbative gr…

hep-lat2026

Heavy-Meson Bag Parameters using Gradient Flow

Matthew Black, Robert V. Harlander, Jonas T. Kohnen +4

We demonstrate the use of the gradient flow combined with the short flow-time expansion (GF+SFTX) as a renormalization procedure for four-quark operator matrix elements and associa…

hep-ph2026

Bag Parameters for Heavy Meson Lifetimes

Matthew Black, Robert V. Harlander, Jonas T. Kohnen +4

We calculate the dimension-six four-quark matrix elements describing heavy-meson lifetime ratios using the gradient flow with its short flow-time expansion as a renormaliza…

hep-lat2026

Renormalized quark masses using gradient flow

Matthew Black, Robert V. Harlander, Anna Hasenfratz +2

We propose a new and simple method for determining the renormalized quark masses from lattice simulations. Renormalized quark masses are an important input to many phenomenological…

hep-ph2026

The gradient-flow coupling of three-and four-dimensional QED

Lars Georg, Robert V. Harlander, Robert H. Mason

We evaluate the QED coupling in the gradient-flow scheme in three and four space-time dimensions. Our general result applies to any theory with a U(1) gauge field coupled to arbita…

hep-lat2025

Quark-mass effects in gradient-flow observables through next-to-next-to-leading order in QCD

Robert V. Harlander, Robert H. Mason

We provide results for the vacuum expectation values of the flowed action density, the quark condensate, and the quark kinetic operator in the gradient-flow formalism. We work in $…