Results 31 to 40 of about 2,346 (181)

Geodesics in the Heisenberg Group

Analysis and Geometry in Metric Spaces, 2015
We provide a new and elementary proof for the structure of geodesics in the Heisenberg group Hn. The proof is based on a new isoperimetric inequality for closed curves in R2n.We also prove that the Carnot- Carathéodory metric is real analytic away from ...
Hajłasz Piotr, Zimmerman Scott
doaj   +1 more source

From the Discovery of the Giant Magnetocaloric Effect to the Development of High‐Power‐Density Systems

Advanced Materials Technologies, EarlyView.
The article overviews past and current efforts on caloric materials and systems, highlighting the contributions of Ames National Laboratory to the field. Solid‐state caloric heat pumping is an innovative method that can be implemented in a wide range of cooling and heating applications.
Agata Czernuszewicz, Yaroslav Mudryk, Jun Cui, Lucas Griffith, Duane D. Johnson, Julie Slaughter   +5 more
wiley   +1 more source

Maximizing the Energy Output of Soft Electrohydraulic Generators

Advanced Science, EarlyView.
Many energy resources cannot be viably harvested with electromagnetic generators. This article evaluates the potential of soft electrohydraulic generators as an alternative approach for energy capture. An analytical model charts their operational limits and a rigorous experimental study results in new performance benchmarks with maximum specific energy
Sophie Kirkman, Ingemar Schmidt, Lawrence T. Smith, Steven L. Zhang, Shane K. Mitchell, Soo Jin Adrian Koh, Philipp Rothemund, Christoph Keplinger   +7 more
wiley   +1 more source

Rectifiability in Carnot Groups

, 2022
This thesis is devoted to the study of the theory of rectifiability of sets and measures in the non smooth context of Carnot groups. The focus is on the study of the notion of P-rectifiability and its relation with other notions of rectifiability in Carnot groups.
openaire   +2 more sources

Uniform Gaussian Bounds for Subelliptic Heat Kernels and an Application to the Total Variation Flow of Graphs over Carnot Groups

Analysis and Geometry in Metric Spaces, 2013
In this paper we study heat kernels associated with a Carnot group G, endowed with a family of collapsing left-invariant Riemannian metrics σε which converge in the Gromov- Hausdorff sense to a sub-Riemannian structure on G as ε→ 0.
Capogna Luca, Citti Giovanna, Manfredini Maria   +2 more
doaj   +1 more source

The Peregrine Breather on the Zero-Background Limit as the Two-Soliton Degenerate Solution: An Experimental Study

Frontiers in Physics, 2021
Solitons are coherent structures that describe the nonlinear evolution of wave localizations in hydrodynamics, optics, plasma and Bose-Einstein condensates.
Amin Chabchoub, Amin Chabchoub, Amin Chabchoub, Alexey Slunyaev, Alexey Slunyaev, Norbert Hoffmann, Norbert Hoffmann, Frederic Dias, Frederic Dias, Bertrand Kibler, Goëry Genty, John M. Dudley, Nail Akhmediev   +12 more
doaj   +1 more source

ZnO Nanowires by Chemical Bath Deposition: A Review on Doping and Functional Devices

Electron, EarlyView.
This review reports the most recent and well‐established state‐of‐the‐art and scientific challenges related to the doping of ZnO nanowires by chemical bath deposition, encompassing native point and hydrogen‐related defects, as well as extrinsic dopants.
Clément Lausecker, Adrien Baillard, Estelle Appert, Vincent Consonni   +3 more
wiley   +1 more source

Subelliptic and parametric equations on Carnot groups [PDF]

Proceedings of the American Mathematical Society, 2015
This article concerns a class of elliptic equations on Carnot groups depending on one real parameter. Our approach is based on variational methods. More precisely, we establish the existence of at least two weak solutions for the treated problem by using a direct consequence of the celebrated Pucci-Serrin theorem and of a local minimum result for ...
Molica Bisci G, Ferrara M
openaire   +5 more sources

On Rectifiable Measures in Carnot Groups: Existence of Density

The Journal of Geometric Analysis, 2022
AbstractIn this paper, we start a detailed study of a new notion of rectifiability in Carnot groups: we say that a Radon measure is$${\mathscr {P}}_h$$Ph-rectifiable, for$$h\in {\mathbb {N}}$$h∈N, if it has positiveh-lower density and finiteh-upper density almost everywhere, and, at almost every point, it admits a unique tangent measure up to multiples.
Gioacchino Antonelli, Andrea Merlo
openaire   +5 more sources

Curvature exponent and geodesic dimension on Sard-regular Carnot groups

Analysis and Geometry in Metric Spaces
In this study, we characterize the geodesic dimension NGEO{N}_{{\rm{GEO}}} and give a new lower bound to the curvature exponent NCE{N}_{{\rm{CE}}} on Sard-regular Carnot groups.
Golo Sebastiano Nicolussi, Zhang Ye
doaj   +1 more source