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The Euclidean formulation of quantum gravity can be interpreted in terms of a probability distribution over Riemannian manifolds. In the context of de Sitter gravity, the statistics of the total volume according to this distribution is…

High Energy Physics - Theory · Physics 2026-05-07 David Blanco , Guillem Pérez-Nadal , Bruno Sivilotti

We study the momentum-space entanglement between the sub- and super-Hubble modes of a spectator scalar field, with a cubic $\lambda \phi^3$ interaction, in de Sitter space. Momentum-space entanglement has some universal properties for any…

High Energy Physics - Theory · Physics 2023-02-28 Suddhasattwa Brahma , Jaime Calderón-Figueroa , Moatasem Hassan , Xuan Mi

This paper extends sliding-mode control theory to nonlinear systems evolving on smooth manifolds. Building on differential geometric methods, we reformulate Filippov's notion of solutions, characterize well-defined vector fields on quotient…

Optimization and Control · Mathematics 2025-09-17 Fernando Castaños

The Lorentzian type IIB matrix model is a promising candidate for a nonperturbative formulation of superstring theory. In this model, the eigenvalue distribution of the $N\times N$ bosonic matrices $A_\mu$ $(\mu = 0 , \ldots , 9)$…

We show how it is possible to formulate Euclidean two-dimensional quantum gravity as the scaling limit of an ordinary statistical system by means of dynamical triangulations, which can be viewed as a discretization in the space of…

High Energy Physics - Theory · Physics 2009-10-28 J. Ambjorn , J. Jurkiewicz , Y. Watabiki

We investigate topology change in (1+1) dimensions by analyzing the scalar-curvature action $1/2 \int R dV$ at the points of metric-degeneration that (with minor exceptions) any nontrivial Lorentzian cobordism necessarily possesses. In two…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Jorma Louko , Rafael D. Sorkin

The recent progress in the Causal Dynamical Triangulations (CDT) approach to quantum gravity indicates that gravitation is nonperturbatively renormalizable. We review some of the latest results in 1+1 and 3+1 dimensions with special…

High Energy Physics - Theory · Physics 2009-11-11 R. Loll , W. Westra , S. Zohren

We study the momentum space entanglement between different energy modes of interacting scalar fields propagating in general (D + 1)-dimensional flat space-time. As opposed to some of the recent works [1], we use Lorentz invariant normalized…

High Energy Physics - Theory · Physics 2017-03-29 S. Santhosh Kumar , S. Shankaranarayanan

Some general remarks are made about the quantum theory of scalar fields and the definition of momentum in curved space. Special emphasis is given to field theory in anti-de Sitter space, as it represents a maximally symmetric space-time of…

High Energy Physics - Theory · Physics 2008-02-03 Simon Davis

We construct two types of scalar field theory on Snyder space-time. The first one is based on the natural momenta addition inherent to the coset momentum space. This construction uncovers a non-associative deformation of the Poincar\'e…

High Energy Physics - Theory · Physics 2011-03-31 Florian Girelli , Etera R. Livine

Studies of periodically driven one-dimensional many-body systems have advanced our understanding of complex systems and stimulated promising developments in quantum simulation. It is hence of interest to go one step further, by…

Quantum Physics · Physics 2021-06-04 Raditya Weda Bomantara , Sen Mu , Jiangbin Gong

We revisit the path-integral approach to the wave function of the Universe by utilizing Lefschetz thimble analyses and resurgence theory. The traditional Euclidean path-integral of gravity has the notorious ambiguity of the direction of…

General Relativity and Quantum Cosmology · Physics 2025-04-17 Masazumi Honda , Hiroki Matsui , Kazumasa Okabayashi , Takahiro Terada

We address the development of geometric phases in classical and quantum magnetic moments (spin-1/2) precessing in an external magnetic field. We show that nonadiabatic dynamics lead to a topological phase transition determined by a change…

Mesoscale and Nanoscale Physics · Physics 2016-04-13 Henri Saarikoski , José Pablo Baltanás , J. Enrique Vázquez-Lozano , Junsaku Nitta , Diego Frustaglia

We analyze the universal properties of a new two-dimensional quantum gravity model defined in terms of Locally Causal Dynamical Triangulations (LCDT). Measuring the Hausdorff and spectral dimensions of the dynamical geometrical ensemble, we…

High Energy Physics - Theory · Physics 2015-10-07 Renate Loll , Ben Ruijl

Understanding the emergence of classical behavior from a quantum theory is vital to establishing the quantum origin for the temperature fluctuations observed in the Cosmic Microwave Background (CMB). We show that a real-space approach can…

General Relativity and Quantum Cosmology · Physics 2024-02-12 S. Mahesh Chandran , Karthik Rajeev , S. Shankaranarayanan

We investigate the causal relations in the space of states of almost commutative Lorentzian geometries. We fully describe the causal structure of a simple model based on the algebra $\mathcal{S}(\mathbb{R}^{1,1}) \otimes M_2(\mathbb{C})$,…

Mathematical Physics · Physics 2014-01-29 Nicolas Franco , Michał Eckstein

The dynamical generation of a four-dimensional classical universe from nothing but fundamental quantum excitations at the Planck scale is a long-standing challenge to theoretical physicists. A candidate theory of quantum gravity which…

High Energy Physics - Theory · Physics 2009-01-08 J. Ambjorn , A. Goerlich , J. Jurkiewicz , R. Loll

We are studying the dynamics of a one-dimensional field in a non-commutative Euclidean space. The non-commutative space we consider is the one that emerges in the context of three dimensional Euclidean quantum gravity: it is a deformation…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Karim Noui

The type IIB matrix model is a promising candidate for a nonperturbative formulation of superstring theory. In the Lorentzian version, in particular, the emergence of (3+1)D expanding space-time was observed by Monte Carlo studies of this…

High Energy Physics - Lattice · Physics 2020-06-02 Jun Nishimura

We investigate the classical limit of non-Hermitian quantum dynamics arising from a coherent state approximation, and show that the resulting classical phase space dynamics can be described by generalised "canonical" equations of motion,…

Quantum Physics · Physics 2010-02-08 Eva-Maria Graefe , Michael Hoening , Hans Juergen Korsch