Results 31 to 40 of about 878,195 (332)

Principal null directions of perturbed black holes [PDF]

, 2003
The properties of principal null directions of a perturbed black hole are investigated. It shown that principal null directions are directly observable quantities characterizing the space-time.
Baker J, Bradley M, Bruni M, Campanelli M, Chandrasekhar S, Chandrasekhar S, Chrobok T, Couch W E, Dain S, Gunnarsen L, Karlhede A, Kinnersley W, Kramer M M D, M Vasúth, Misner C, Newman E T, Penrose R, Stewart J M, van den Brink A M, Wald R M, Z Perjés   +20 more
core   +1 more source

Estimating null and potent modes of feedforward communication in a computational model of cortical activity

Scientific Reports, 2022
Communication across anatomical areas of the brain is key to both sensory and motor processes. Dimensionality reduction approaches have shown that the covariation of activity across cortical areas follows well-delimited patterns.
Jean-Philippe Thivierge, Artem Pilzak
doaj   +1 more source

Online Cartesian Compliance Shaping of Redundant Robots in Assembly Tasks

Machines, 2022
This paper presents a universal approach to shaping the mechanical properties of the interaction between a collaborative robot and its environment through an end-effector Cartesian compliance shaping.
Branko Lukić, Kosta Jovanović, Leon Žlajpah, Tadej Petrič   +3 more
doaj   +1 more source

Exact solutions of closed string theory [PDF]

, 1995
We review explicitly known exact $D=4$ solutions with Minkowski signature in closed bosonic string theory. Classical string solutions with space-time interpretation are represented by conformal sigma models.
A A Tseytlin, Bardakci K, Bars I, Bars I, Behrndt K, Brinkmann H W, Callan C, Callan C, De Alwis S, de Boer J, de Vega H, de Vega H, Duff M, Duff M J, Duval C, Ferrara S, Figueroa-O'Farrill J M, Forgács P, Forgács P, Fradkin E S, Fradkin E S, Friedan D, Friedan D, Galtsov D, Gauntlett J, Gibbons G W, Gürses M, Halpern M B, Halpern M B, Horowitz G, Horowitz G, Horowitz G, Horowitz G T, Howe P, Israel W, Johnson C, Kallosh R, Kehagias A, Khuri R, Kiritsis E, Kiritsis E, Kiritsis E, Kounnas C, Kounnas C, Lovelace C, Mohammedi N, Morozov A Yu, Mukhi S, Nesterenko V V, Park J, Penrose R, Peterman A, Peterman A, Polyakov A, Polyakov A M, Russo J G, Russo J G, Russo J G, Sfetsos K, Sfetsos K, Townsend P K, Tseytlin A A, Tseytlin A A, Witten E, Yoneya T, Zamolodchikov A B   +65 more
core   +2 more sources

Simultaneous Multislice Brain MRI T1 Mapping with Improved Low-Rank Modeling

Tomography, 2021
To accelerate data acquisition speed in magnetic resonance imaging (MRI), multiple slices are simultaneously acquired using multiband pulses. Simultaneous multislice (SMS) imaging typically unfolds slice aliasing from the acquired collapsed slices.
Sugil Kim, Suhyung Park
doaj   +1 more source

Particle Number and 3D Schroedinger Holography [PDF]

, 2013
We define a class of space-times that we call asymptotically locally Schroedinger space-times. We consider these space-times in 3 dimensions, in which case they are also known as null warped AdS.
Hartong, Jelle, Rollier, Blaise
core   +2 more sources

Homogeneous two-point problem for PDE of the second order in time variable and infinite order in spatial variables

Open Mathematics, 2017
We prove that homogeneous problem for PDE of second order in time variable, and generally infinite order in spatial variables with local two-point conditions with respect to time variable, has only trivial solution in the case when the characteristic ...
Malanchuk Oksana, Nytrebych Zinoviy
doaj   +1 more source

Null-vectors in Integrable Field Theory [PDF]

, 1997
The form factor bootstrap approach allows to construct the space of local fields in the massive restricted sine-Gordon model. This space has to be isomorphic to that of the corresponding minimal model of conformal field theory.
D. Bernard B, F. A. Smirnov, O. Babelon A, Service Physique, Théorique Saclay   +4 more
core   +6 more sources

Darboux Associated Curves of a Null Curve on Pseudo-Riemannian Space Forms

Mathematics, 2020
In this work, the Darboux associated curves of a null curve on pseudo-Riemannian space forms, i.e., de-Sitter space, hyperbolic space and a light-like cone in Minkowski 3-space are defined.
Jinhua Qian, Xueshan Fu, Seoung Dal Jung   +2 more
doaj   +1 more source

Muscle patterns underlying voluntary modulation of co-contraction. [PDF]

PLoS ONE, 2018
Manipulative actions involving unstable interactions with the environment require controlling mechanical impedance through muscle co-contraction.
Daniele Borzelli, Benedetta Cesqui, Denise J Berger, Etienne Burdet, Andrea d'Avella   +4 more
doaj   +1 more source