Results 91 to 100 of about 166,028,825 (289)
Incompatibility of gravity theories with auxiliary fields with the standard model [PDF]
Theories of gravity with auxiliary fields are of particular interest since they are able to circumvent Lovelock’s theorem while avoiding the introduction of new degrees of freedom.
Pani, Paolo +2 more
core +1 more source
Geometric selection rules for singularity formation in modified gravity
European Physical Journal C: Particles and FieldsWe argue that the polynomial degeneracies of curvature invariants can act as geometric selection rules for spacetime singularities in modified theories of gravity.
Soumya Chakrabarti
doaj +1 more source
Asymmetry in Skipping Enhances Viability Against Control Input Noise
Advanced Robotics Research, EarlyView.Quadruped animals use asymmetric galloping gaits at high speeds, yet the functional role of this asymmetry remains unclear. This study shows that left–right asymmetry in touchdown angles enhances robustness to control noise. Using a simple two‐legged locomotion model and viability theory, it demonstrates that asymmetric skipping substantially enlarges ...
Yuichi Ambe, Alvin So, Shinya Aoi
wiley +1 more source
Strings, branes, and gravity duals of gauge theories [PDF]
, 2002 We study the correspondence between certain supersymmetric gauge theories and their dual supergravity descriptions. Using low-energy brane probes of the super-gravity geometries we find moduli spaces of vacua, as expected from considering the dual gauge ...
Lovis, Kenneth John
core
The solar system test for the general modified gravity theories
, 2022 In the past few decades, various versions of modified gravity theories were proposed to mimic the effect of dark matter. Compared with the conventional Newtonian or relativistic dynamics, these theories contain some extra apparent force terms in the ...
Lee, Chak Man, Chan, Man Ho
core +1 more source
Living Reviews in Relativity, 2010 Over the past decade, f(R) theories have been extensively studied as one of the simplest modifications to General Relativity. In this article we review various applications of f(R) theories to cosmology and gravity – such as inflation, dark energy, local
Antonio De Felice, Shinji Tsujikawa
doaj
The dark side of gravity: Modified theories of gravity
, 2008 17 pages, invited chapter to appear in an edited collection 'Dark Energy-Current Advances and Ideas'
openaire +2 more sources
Continuum Mechanics Modeling of Flexible Spring Joints in Surgical Robots
Advanced Robotics Research, EarlyView.A new mechanical model of a tendon‐actuated helical extension spring joint in surgical robots is built using Cosserat rod theory. The model can implicitly handle the unknown contacts between adjacent coils and numerically predict spring shapes from straight to significantly bent under actuation forces.
Botian Sun +3 more
wiley +1 more source
Origami‐Inspired Structural Design for Aquatic‐Terrestrial Amphibious Robots
Advanced Robotics Research, EarlyView.This work presents a lightweight amphibious origami robot actuated by a single shape memory alloy wire. A rigid foldable origami structure with displacement amplification enables efficient terrestrial crawling and aquatic swimming. The addition of fan‐shaped units allows controllable turning in both environments.
Weiqi Liu +5 more
wiley +1 more source
A Soft Robotic Fish With a Dielectric Elastomer Actuator Body and Negative Stiffness Spine
Advanced Robotics Research, EarlyView.This work introduces a bio‐mimetic soft robotic fish driven by fiber‐reinforced dielectric elastomer actuators integrated as its body. By prestretching this active skin against a flexible spine, a negative stiffness system is created, enabling large‐amplitude bending.
Markus Koenigsdorff +4 more
wiley +1 more source