Publications associées à Vacuum solution (general relativity)

Critical degeneracy in a nonlinear hyperbolic equation can produce atypical instability

This paper deals with the initial value problem for a semilinear wave equation on a bounded domain and solutions are required to vanish on the boundary of this domain. The essential feature of the situation considered here is that the ellipticity of the sp ...

2024

Backtracking Dynamical Cavity Method

Lenka Zdeborová, Freya Behrens, Barbora Hudcová

The cavity method is one of the cornerstones of the statistical physics of disordered systems such as spin glasses and other complex systems. It is able to analytically and asymptotically exactly describe the equilibrium properties of a broad range of mode ...

American Physical Society2023

Comment on “Groundwater Affects the Geomorphic and Hydrologic Properties of Coevolved Landscapes” by Litwin et al

Sara Bonetti, Shashank Kumar Anand

The objective of this comment is to correct two sets of statements in Litwin et al. (2022, https://doi.org/10.1029/2021JF006239), which consider our research work (Bonetti et al., 2018, https://doi.org/10.1098/rspa.2017.0693; Bonetti et al., 2020, https:// ...

2022

PMT: Power Measurement Toolkit

Emma Elizabeth Tolley, Stefano Corda

Efficient use of energy is essential for today's supercomputing systems, as energy cost is generally a major component of their operational cost. Research into "green computing" is needed to reduce the environmental impact of running these systems. As such ...

IEEE COMPUTER SOC2022

Reconfigurable Timed Discrete-Event Systems

Matin Macktoobian

In this paper, we present the first general solution to the automatic reconfiguration problem of timed discrete-event systems. We extend the recursive forcible backtracking approach which had been already solved the automatic reconfiguration problem of unt ...

IEEE2020

Dynamical collapse of cylindrical symmetric Dipolar Bose-Einstein condensates

Luigi Forcella

We study the formation of singularities for cylindrical symmetric solutions to the Gross-Pitaevskii equation describing a Dipolar Bose-Einstein condensate. We prove that solutions arising from initial data with energy below the energy of the Ground State a ...

2021

Brownian Swarm Dynamics and Burgers’ Equation with Higher Order Dispersion

Max-Olivier Hongler

he concept of ranked order probability distribution unveils natural probabilistic interpretations for the kink waves (and hence the solitons) solving higher order dispersive Burgers’ type PDEs. Thanks to this underlying structure, it is possible to propose ...

2020

Two-fluid plasma model for radial Langmuir probes as a converging nozzle with sonic choked flow, and sonic passage to supersonic flow

Ivo Furno, Alan Howling, Philippe Frédérique Bruno Guittienne

Using the Lambert function, Guittienne et al. [Phys. Plasmas 25, 093519 (2018)] derived two-fluid solutions for radial Langmuir probes in collisionless and isothermal plasma. In this Brief Communication, we point out the close analogy with classical compre ...

American Institute of Physics (AIP)2019

On the Soil-Structure Interaction of Surface Strip Footings at Ultimate Limit State

Lyesse Laloui, Cristiano Garbellini

Theoretical methods for estimating the bearing capacity of surface strip footings usually do not consider soil-structure interaction. A few publications deal with the subject, but all of these either do not apply rigorous methods or do not consider the gen ...

ISSMGE2018

Behaviour of a scour protection overlay with randomly distributed concrete prisms in plunge pools downstream of mobile barrages for exceptional operation conditions

Anton Schleiss, Giovanni De Cesare, Pedro Filipe De Almeida Manso, Sabine Chamoun, Davide Wüthrich

Uncontrolled scour is affecting multiple mobile dams. The plunge pool of the Chancy-Pougny barrage, located on the Rhone River bordering France and Switzerland, has recently been reported to develop in a potentially unfavourable direction after almost 100 ...

2018

Dexterous Underwater Manipulation from Distant Onshore Locations

Sylvain Calinon, Ajay Kumar Tanwani

Underwater manipulation is a challenging problem. The state of the art is dominated by Remotely Operated Vehicles (ROV). ROV operations typically require an offshore crew consisting of at least an intendant, an operator, and a navigator. This crew often ha ...

2018

Development of a consistent approach for design and assessment of structural concrete members using stress fields and strut-and-tie models

Filip Niketic

Designing new concrete members and assessing the strength of existing elements subjected to in-plane stress state conditions is often conducted by means of Stress Fields (SF) and Strut-and-Tie Models (STM). These methods are usually accounting for identica ...

EPFL2017

Phenotypic heterogeneity driven by nutrient limitation promotes growth in fluctuating environments

Anders Meibom, Stéphane Laurent Escrig, Martin Ackermann

Most microorganisms live in environments where nutrients are limited and fluctuate over time. Cells respond to nutrient fluctuations by sensing and adapting their physiological state. Recent studies suggest phenotypic heterogeneity(1) in isogenic populatio ...

Nature Publishing Group2016

Stresses and displacements in steel-lined pressure tunnels and shafts in anisotropic rock under quasi-static internal water pressure

Anton Schleiss, Alexandre Jean Pachoud

Steel-lined pressure tunnels and shafts are constructed to convey water from reservoirs to hydroelectric power plants. They are multilayer structures made of a steel liner, a cracked backfill concrete layer, a cracked or loosened near-field rock zone and a ...

Springer Wien2016

Asymmetric breaking size-segregation waves in dense granular free-surface flows

Christophe Ancey, Kasper van der Vaart

Debris and pyroclastic flows often have bouldery flow fronts, which act as a natural dam resisting further advance. Counter intuitively, these resistive fronts can lead to enhanced run-out, because they can be shouldered aside to form static levees that se ...

Cambridge University Press2016

Design versus Assessment of Concrete Structures Using Stress Fields and Strut-and-Tie Models

Aurelio Muttoni, Miguel Fernández Ruiz, Filip Niketic

Stress fields and strut-and-tie models are widely used for design and assessment of structural concrete members. Although they are often used in the same manner for both purposes, developing suitable stress fields and strut-and-tie models for the design of ...

2015

Codimension one stability of the catenoid under the vanishing mean curvature flow in Minkowski space

Joachim Krieger, Roland Donninger, Willie Wai Yeung Wong

We study time-like hypersurfaces with vanishing mean curvature in the (3+1) dimensional Minkowski space, which are the hyperbolic counterparts to minimal embeddings of Riemannian manifolds. The catenoid is a stationary solution of the associated Cauchy pro ...

Duke Univ Press2015

Exotic blow up solutions for the $\Box u^5$-focussing wave equation in $\mathbb{R}^3$

Joachim Krieger, Roland Donninger, Min Huang

For the critical focusing wave equation

\Box u = u^5

on

\mathbb{R}^{3+1}

in the radial case, we construct a family of blowup solutions which are obtained from the stationary solutions

W(r)

by means of a dynamical rescaling $\lambda(t)\frac{1}{2}W(\la ...

Michigan Mathematical Journal2014

Nondispersive Decay For The Cubic Wave Equation

Roland Donninger

We consider the hyperboloidal initial value problem for the cubic focusing wave equation (-partial derivative(2)(t) + Delta(x))nu(t, x) + nu(t, x)(3) = 0, x is an element of R-3 Without symmetry assumptions, we prove the existence of a codimension-4 Lipsch ...

Mathematical Science Publ2014

Structured Canonical Forms For Products Of (Skew-) Symmetric Matrices And The Matrix Equation XAX = B

Daniel Kressner, Xin Liu

The contragredient transformation A bar right arrow P-1 AP-(inverted perpendicular) , B bar right arrow P-inverted perpendicular BP of two matrices A, B effects simultaneous similarity transformations of the products AB and BA. This work provides structure ...

Int Linear Algebra Soc2013