70 citations · 613 across the 30 of their papers we have counts for
30 papers
Simplicial Graviton from Selfdual Ashtekar Variables
Wolfgang Wieland
In perturbative gravity, it is straight-forward to characterize the two local degrees of freedom of the gravitational field in terms of a mode expansion of the linearized perturbat…
Corner symmetry and quantum geometry
Laurent Freidel, Marc Geiller, Wolfgang Wieland
By virtue of the Noether theorems, the vast gauge redundancy of general relativity provides us with a rich algebra of boundary charges that generate physical symmetries. These char…
Quantum Reference Frames at the Boundary of Spacetime
Viktoria Kabel, Časlav Brukner, Wolfgang Wieland
An analysis is given of the local phase space of gravity coupled to matter to second order in perturbation theory. Working in local regions with boundaries at finite distance, we i…
Metriplectic geometry for gravitational subsystems
Viktoria Kabel, Wolfgang Wieland
In general relativity, it is difficult to localise observables such as energy, angular momentum, or centre of mass in a bounded region. The difficulty is that there is dissipation.…
Gravitational Algebra on the Light Cone
Wolfgang Wieland
In a region with a boundary, the gravitational phase space consists of radiative modes in the interior and edge modes at the boundary. Such edge modes are necessary to explain how…
Barnich-Troessaert Bracket as a Dirac Bracket on the Covariant Phase Space
Wolfgang Wieland
The Barnich--Troessaert bracket is a proposal for a modified Poisson bracket on the covariant phase space for general relativity. The new bracket allows us to compute charges, whic…
Canonical transformations generated by the boundary volume: Unimodular and non-Abelian teleparallel gravity
Florian Girelli, Abdulmajid Osumanu, Wolfgang Wieland
Recently, a new choice of variables was identified to understand how the quantum group structure appeared in three-dimensional gravity [1]. These variables are introduced via a can…
Null infinity as an open Hamiltonian system
Wolfgang Wieland
When a system emits gravitational radiation, the Bondi mass decreases. If the Bondi energy is Hamiltonian, it can thus only be a time dependent Hamiltonian. In this paper, we show…
Twistor representation of Jackiw-Teitelboim gravity
Wolfgang Wieland
Jackiw-Teitelboim (JT) gravity is a 1+1-dimensional toy model for quantum gravity in four spacetime dimensions. In the absence of matter, JT gravity is a topological field theory a…
Deformed Heisenberg charges in three-dimensional gravity
Jeevan Chandra Namburi, Wolfgang Wieland
In this paper, we consider the bulk plus boundary phase space for three-dimensional gravity with negative cosmological constant for a particular choice of conformal boundary condit…
First-order formulation of teleparallel gravity and dual loop gravity
Maïté Dupuis, Florian Girelli, Abdulmajid Osumanu +1
There are at least two ways to encode gravity into geometry: Einstein's general theory of relativity (GR) for the metric tensor, and teleparallel gravity, where torsion as opposed…
Generating functional for gravitational null initial data
Wolfgang Wieland
A field theory on a three-dimensional manifold is introduced, whose field equations are the constraint equations for general relativity on a three-dimensional null hypersurface. Th…
Conformal boundary conditions, loop gravity and the continuum
Wolfgang Wieland
In this paper, we will make an attempt to clarify the relation between three-dimensional euclidean loop quantum gravity with vanishing cosmological constant and quantum field theor…
Cosmological evolution as squeezing: a toy model for group field cosmology
Eugene Adjei, Steffen Gielen, Wolfgang Wieland
We present a simple model of quantum cosmology based on the group field theory (GFT) approach to quantum gravity. The model is formulated on a subspace of the GFT Fock space for th…
Quantum gravity in three dimensions, Witten spinors and the quantisation of length
Wolfgang Wieland
In this paper, I investigate the quantisation of length in euclidean quantum gravity in three dimensions. The starting point is the classical hamiltonian formalism in a cylinder of…
Fock representation of gravitational boundary modes and the discreteness of the area spectrum
Wolfgang Wieland
In this article, we study the quantum theory of gravitational boundary modes on a null surface. These boundary modes are given by a spinor and a spinor-valued two-form, which enter…
New boundary variables for classical and quantum gravity on a null surface
Wolfgang Wieland
The covariant Hamiltonian formulation for general relativity is studied in terms of self-dual variables on a manifold with an internal and lightlike boundary. At this inner boundar…
Discrete gravity as a topological field theory with light-like curvature defects
Wolfgang Wieland
I present a model of discrete gravity, which is formulated in terms of a topological gauge theory with defects. The theory has no local degrees of freedom and the gravitational fie…
Quasi-local gravitational angular momentum and centre of mass from generalised Witten equations
Wolfgang Wieland
Witten's proof for the positivity of the ADM mass gives a definition of energy in terms of three-surface spinors. In this paper, we give a generalisation for the remaining six Poin…
New action for simplicial gravity in four dimensions
Wolfgang M. Wieland
We develop a proposal for a theory of simplicial gravity with spinors as the fundamental configuration variables. The underlying action describes a mechanical system with finitely…
A one-dimensional action for simplicial gravity in three dimensions
Wolfgang M. Wieland
This article presents a derivation of the Ponzano--Regge model from a one-dimensional spinor action. The construction starts from the first-order Palatini formalism in three dimens…
Hamiltonian spinfoam gravity
Wolfgang M. Wieland
This paper presents a Hamiltonian formulation of spinfoam-gravity, which leads to a straight-forward canonical quantisation. To begin with, we derive a continuum action adapted to…
The spin connection of twisted geometry
Hal M. Haggard, Carlo Rovelli, Francesca Vidotto +1
Twisted geometry is a piecewise-flat geometry less rigid than Regge geometry. In Loop Gravity, it provides the classical limit for each step of the truncation utilized in the defin…
The twistorial structure of loop-gravity transition amplitudes
Simone Speziale, Wolfgang M. Wieland
The spin foam formalism provides transition amplitudes for loop quantum gravity. Important aspects of the dynamics are understood, but many open questions are pressing on. In this…