Results 81 to 90 of about 6,479 (312)
Gravity waves in classical string theory
Nuclear Physics B, 1992 Abstract Gravity waves that serve as conformally invariant bavkgrounds for the string sigma model can create space-time singularities when they collide. We describe some of the properties and pathologies of these waves, and compute the O(α′) perturbation to the metric for the space-time with two colliding plane waves.
openaire +1 more source
A2: Mathematical relativity and other progress in classical gravity theory—a session report [PDF]
General Relativity and Gravitation, 2014 13 pages, some minor ...
Chrusciel, Piotr T., Paetz, Tim-Torben
openaire +4 more sources
Advanced Materials, EarlyView.Stacked nanoflake assembly (SNA) membranes can oscillate autonomously, offering opportunities for soft actuation and energy harvesting. This work uncovers the physical mechanism behind the sustained oscillation of SNA membranes in gradient humidity and identifies three governing dimensionless parameters, enabling rational design for optimizing SNA ...
Zijing Zhang +5 more
wiley +1 more source
A Classical Field Theory of Gravity and Electromagnetism
Journal of Modern Physics, 2014 A classical field theory of gravity and electromagnetism is developed. The starting point of the theory is the Maxwell equations which are directly tied to the Riemann-Christoffel curvature tensor. This is done through the derivatives of the Maxwell tensor which are equated to a vector field contracted with the ...
openaire +2 more sources
Advanced Materials Technologies, EarlyView.This study formulated a 5Y‐PSZ zirconia paste for extrusion‐based additive manufacturing via direct ink writing, producing dense ceramic structures for dental applications. A colloidal approach with 47 vol% nanometric powder and tailored additives optimized rheology and printability.
Juliana de Freitas Gouveia Silva +5 more
wiley +1 more source
Self-dual pp-wave solutions in chiral higher-spin gravity
Journal of High Energy PhysicsWe show that chiral higher-spin gravity with a vanishing cosmological constant admits a class of exact self-dual pp-wave solutions derived from harmonic scalar functions and two principal spinors.
Tung Tran
doaj +1 more source
Hard‐Magnetic Soft Millirobots in Underactuated Systems
Advanced Robotics Research, EarlyView.This review provides a comprehensive overview of hard‐magnetic soft millirobots in underactuated systems. It examines key advances in structural design, physics‐informed modeling, and control strategies, while highlighting the interplay among these domains.
Qiong Wang +4 more
wiley +1 more source
Advanced Robotics Research, EarlyView.Pak Biawak, a necrobot, embodies an unusual fusion of biology and robotics. Designed to repurpose natural structures after death, it challenges conventional boundaries between nature and engineering. Its movements are precise yet unsettling, raising questions about sustainability, ethics, and the untapped potential of biointegrated machines.
Leo Foulds +2 more
wiley +1 more source
, 2010 The observable universe could be a 1+3-surface (the “brane”) embedded in a 1+3+d-dimensional spacetime (the “bulk”), with Standard Model particles and fields trapped on the brane while gravity is free to access the bulk.
Roy Maartens +3 more
core +1 more source
Advanced Science, EarlyView.Nanocellulose, derived from microcrystalline cellulose (MCC) through sulfuric acid hydrolysis or mechanical grinding to produce CNC or CNF, was tested in a rat ICP model. Particularly, CNF improved gut microbiota composition, reduced secondary bile acid metabolism, and restored bile acid homeostasis through modulation of the gut–liver axis.
Muhua Yu +18 more
wiley +1 more source