Zobrazeno 1 - 10
of 3 973
pro vyhledávání: '"P. Gielen"'
Autor:
Gielen, Steffen
Group field theory is a background-independent approach to quantum gravity whose starting point is the definition of a quantum field theory on an auxiliary group manifold (not interpreted as spacetime). Group field theory models can be seen as an ext
Externí odkaz:
http://arxiv.org/abs/2412.07847
Autor:
Gielen, Steffen, Neves, Rita B.
We study the quantum dynamics of de Sitter space formulated as a minisuperspace model with flat spatial hypersurfaces in unimodular gravity, both in the Wheeler-DeWitt approach and in loop quantum cosmology (LQC). Time evolution is defined naturally
Externí odkaz:
http://arxiv.org/abs/2412.01907
Autor:
Gielen, Steffen, Nash, Elliot
We present the canonical analysis of different versions of unimodular gravity defined in the Pleba\'nski formalism, based on a (generally complex) SO(3) spin connection and set of (self-dual) two-forms. As in the metric formulation of unimodular grav
Externí odkaz:
http://arxiv.org/abs/2411.09748
Autor:
Gielen, Steffen, Menéndez-Pidal, Lucía
We study the quantum dynamics of an interior planar AdS (anti-de Sitter) black hole, requiring unitarity in the natural time coordinate conjugate to the cosmological "constant of motion" appearing in unimodular gravity. Both the classical singularity
Externí odkaz:
http://arxiv.org/abs/2409.03006
Autor:
Calcinari, Andrea, Gielen, Steffen
Group field theory posits that spacetime is emergent and is hence defined without any background notion of space or time; dynamical questions are formulated in relational terms, in particular using (scalar) matter degrees of freedom as time. Unlike i
Externí odkaz:
http://arxiv.org/abs/2407.03432
Autor:
Shang, Meng, Dedeyne, Lenore, Dupont, Jolan, Vercauteren, Laura, Amini, Nadjia, Lapauw, Laurence, Gielen, Evelien, Verschueren, Sabine, Varon, Carolina, De Raedt, Walter, Vanrumste, Bart
The Otago Exercise Program (OEP) serves as a vital rehabilitation initiative for older adults, aiming to enhance their strength and balance, and consequently prevent falls. While Human Activity Recognition (HAR) systems have been widely employed in r
Externí odkaz:
http://arxiv.org/abs/2405.12711
Autor:
Safa, Ali, Jaltare, Vikrant, Sebt, Samira, Gano, Kameron, Leugering, Johannes, Gielen, Georges, Cauwenberghs, Gert
This paper studies the use of Metropolis-Hastings sampling for training Spiking Neural Network (SNN) hardware subject to strong unknown non-idealities, and compares the proposed approach to the common use of the backpropagation of error (backprop) al
Externí odkaz:
http://arxiv.org/abs/2402.06284
Autor:
Shang, Meng, Dedeyne, Lenore, Dupont, Jolan, Vercauteren, Laura, Amini, Nadjia, Lapauw, Laurence, Gielen, Evelien, Verschueren, Sabine, Varon, Carolina, De Raedt, Walter, Vanrumste, Bart
The Otago Exercise Program (OEP) represents a crucial rehabilitation initiative tailored for older adults, aimed at enhancing balance and strength. Despite previous efforts utilizing wearable sensors for OEP recognition, existing studies have exhibit
Externí odkaz:
http://arxiv.org/abs/2402.02910
Autor:
Gielen, Steffen, Mickel, Lisa
Publikováno v:
Class. Quant. Grav. 41 (2024) 165002
We study a group field theory (GFT) for quantum gravity coupled to four massless scalar fields, using these matter fields to define a (relational) coordinate system. We exploit symmetries of the GFT action, in particular under shifts in the values of
Externí odkaz:
http://arxiv.org/abs/2312.10016
Autor:
Calcinari, Andrea, Gielen, Steffen
Publikováno v:
Phys. Rev. D 109 (2024), 066022
We define generalised Gaussian states for quantum cosmological models based on the $\mathfrak{su(1,1)}$ algebra, with particular emphasis on its realisation in group field theory for a single field mode, and study their semiclassical properties. Thes
Externí odkaz:
http://arxiv.org/abs/2310.08667