Lorentzian spacetimes with constant curvature invariants in four dimensions

2009 ◽  
Vol 26 (12) ◽  
pp. 125011 ◽  
Author(s):  
Alan Coley ◽  
Sigbjørn Hervik ◽  
Nicos Pelavas
Keyword(s):  
Constant Curvature ◽  
Four Dimensions ◽  
Curvature Invariants

scholarly journals Kinematic formula and tube formula in space of constant curvature

1990 ◽  
Vol 33 (1) ◽  
pp. 79-88
Author(s):  
Sungyun Lee
Keyword(s):  
Euclidean Space ◽  
Euler Characteristic ◽  
Constant Curvature ◽  
Kinematic Formula ◽  
Curvature Invariants ◽  
Space Of Constant Curvature

The Euler characteristic of an even dimensional submanifold in a space of constant curvature is given in terms of Weyl's curvature invariants. A derivation of Chern's kinematic formula in non-Euclidean space is completed. As an application of above results Weyl's tube formula about an odd-dimensional submanifold in a space of constant curvature is obtained.

scholarly journals Supersymmetry in spaces of constant curvature

2005 ◽  
Vol 83 (1) ◽  
pp. 23-46 ◽  
Author(s):  
D.G.C. McKeon ◽  
T N Sherry
Keyword(s):  
Constant Curvature ◽  
De Sitter ◽  
Spaces Of Constant Curvature ◽  
Four Dimensions

Supersymmetry is considered in spaces of constant curvature (spherical, de Sitter and anti-de Sitter spaces) of two, three, and four dimensions. PACS Nos.: 11.30.Pb, 11.30.Pg}

scholarly journals Lorentzian spacetimes with constant curvature invariants in three dimensions

2007 ◽  
Vol 25 (2) ◽  
pp. 025008 ◽  
Author(s):  
Alan Coley ◽  
Sigbjørn Hervik ◽  
Nicos Pelavas
Keyword(s):  
Constant Curvature ◽  
Three Dimensions ◽  
Curvature Invariants

scholarly journals Curvature Invariants for the Alcubierre and Natário Warp Drives

Universe ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 21 ◽  
Author(s):  
Brandon Mattingly ◽  
Abinash Kar ◽  
Matthew Gorban ◽  
William Julius ◽  
Cooper K. Watson ◽  
...  
Keyword(s):  
Constant Curvature ◽  
Constant Velocity ◽  
Shape Function ◽  
Skin Depth ◽  
Safe Harbor ◽  
Field Equations ◽  
Curvature Invariants ◽  
Unique Effect ◽  
Coordinate Mapping ◽  
Faster Than Light

A process for using curvature invariants is applied to evaluate the metrics for the Alcubierre and the Natário warp drives at a constant velocity. Curvature invariants are independent of coordinate bases, so plotting these invariants will be free of coordinate mapping distortions. As a consequence, they provide a novel perspective into complex spacetimes, such as warp drives. Warp drives are the theoretical solutions to Einstein’s field equations that allow for the possibility for faster-than-light (FTL) travel. While their mathematics is well established, the visualisation of such spacetimes is unexplored. This paper uses the methods of computing and plotting the warp drive curvature invariants to reveal these spacetimes. The warp drive parameters of velocity, skin depth and radius are varied individually and then plotted to see each parameter’s unique effect on the surrounding curvature. For each warp drive, this research shows a safe harbor and how the shape function forms the warp bubble. The curvature plots for the constant velocity Natário warp drive do not contain a wake or a constant curvature, indicating that these are unique features of the accelerating Natário warp drive.

FACT-2 – The Frankfurt Adaptive Concentration Test

2009 ◽  
Vol 25 (2) ◽  
pp. 73-82 ◽  
Author(s):  
Frank Goldhammer ◽  
Helfried Moosbrugger ◽  
Sabine A. Krawietz
Keyword(s):  
Convergent Validity ◽  
Four Dimensions ◽  
Measurement Models ◽  
Cognitive Failures ◽  
Concentration Test ◽  
Cognitive Failures Questionnaire

The Frankfurt Adaptive Concentration Test (FACT-2) requires discrimination between geometric target and nontarget items as quickly and accurately as possible. Three forms of the FACT-2 were constructed, namely FACT-I, FACT-S, and FACT-SR. The aim of the present study was to investigate the convergent validity of the FACT-SR with self-reported cognitive failures. The FACT-SR and the Cognitive Failures Questionnaire (CFQ) were completed by 191 participants. The measurement models confirmed the concentration performance, concentration accuracy, and concentration homogeneity dimensions of FACT-SR. The four dimensions of the CFQ (i.e., memory, distractibility, blunders, and names) were not confirmed. The results showed moderate convergent validity of concentration performance, concentration accuracy, and concentration homogeneity with two CFQ dimensions, namely memory and distractibility/blunders.

Center of Mass Theorem and the Separation of Variables for Two-Body System on a Three-Dimensional Sphere

2020 ◽  
Vol 23 (3) ◽  
pp. 306-311
Author(s):  
Yu. Kurochkin ◽  
Dz. Shoukavy ◽  
I. Boyarina
Keyword(s):  
Constant Curvature ◽  
Jacobi Equation ◽  
Separation Of Variables ◽  
Center Of Mass ◽  
Three Dimensional ◽  
Relative Distance ◽  
Dimensional Sphere ◽  
Body System ◽  
Spaces Of Constant Curvature ◽  
Hamilton Jacobi Equation

The immobility of the center of mass in spaces of constant curvature is postulated based on its definition obtained in [1]. The system of two particles which interact through a potential depending only on the distance between particles on a three-dimensional sphere is considered. The Hamilton-Jacobi equation is formulated and its solutions and trajectory equations are found. It was established that the reduced mass of the system depends on the relative distance.

The Four Dimensions Of The Catalan Model

2000 ◽  
Vol 33 (First Serie (1) ◽  
pp. 100-111
Author(s):  
Pau Piuig i Scotoni
Keyword(s):  
Four Dimensions

A JOURNEY TO MEASURE STUDENT COMMUNITY ENGAGEMENT BENEFITS: EVIDENCE FROM AUSTRALIA

2019 ◽  
Vol 1 (1) ◽  
pp. 16
Author(s):  
Ellen Chung ◽  
Hamish B Coates
Keyword(s):  
Community Engagement ◽  
Undergraduate Students ◽  
Factor Loading ◽  
Higher Learning ◽  
Four Dimensions ◽  
Student Community ◽  
Institutions Of Higher Learning ◽  
Final Questionnaire ◽  
Civic Skills ◽  
Career Skills

Community engagement is a phenomenon that has received increasing attention among institutions of higher learning in recent years, and students engaging with communities are generally seen as beneficial. Given this, surprisingly little is known about this form of engagement in Australian higher education, let alone methods to measure its benefits on students. This study discussed the development of the Student Community Engagement Benefits Questionnaire (SCEBS), a questionnaire that measures the perceptions of community engagement benefits among undergraduate students in Australia. The final questionnaire has 32 items allocated to four benefit scales: (1) Career skills, (2) Diversity skills, (3) Interpersonal skills, (4) Civic skills. Most benefit items had a factor loading of atleast 0.40 with its own scale. The results of the factor analysis revealed that the four scales accounted for 53% of the total variance. The alpha reliability coefficient for the four scales ranged from 0.79 to 0.91. Based on these findings, the Student Community Engagement Benefits Scale (SCEBS) is a valid and reliable instrument that can be used in the field of education. Undergraduate students also reported statistically significant changes in the four dimensions after participating in community engagement activities.

Gender and belief factors on attitude towards Social and Environmental Accounting (SEA)

2009 ◽  
Vol 6 (2) ◽  
pp. 51
Author(s):  
Salina Abdullah ◽  
Ern Chen Loo
Keyword(s):  
Natural Resources ◽  
Undergraduate Students ◽  
Environmental Issues ◽  
Environmental Accounting ◽  
Future Generations ◽  
Business And Society ◽  
Four Dimensions ◽  
Sustain Ability ◽  
The Relationship

Research on social and environmental accounting (SEA) has mainly concentrated on disclosure of SEA by corporate bodies, where investigations on ones attitude towards SEA are rarely discussed. SEA is a medium that develops relationships between business and society, community and nature. In addition, SEA involves a concept of sustain ability; where natural resources need to be sustained for the needs of future generations (Alhabshi et al., 2003). SEA also tries to recognise the role of accounting in sustainable development and the use of environmental resources. There are arguments that the young generations today are not fully aware of preserving these natural resources as well as handling social and environmental issues wisely. This perhaps link closely to their belief and cultural background. Hence, this paper examines the influence of gender and belief factors on the undergraduate students’ attitude towards SEA. Four dimensions of belief (fixed ability, quick learning, simple knowledge and certain knowledge) proposed by Schommer (2005) were adapted to analyse how belief factors have influence on their attitude towards SEA. An independent sample t-test was used to examine the relationship between gender and students’ attitude towards SEA. Spearmen’s correlation was employed to show the relationship between belief and attitude towards SEA. The results revealed that gender differences did not show influences on their attitude towards SEA. It was found that there is a significant relationship between belief and students’ attitude towards SEA. Students who believe on the importance of SEA tend to report positive attitude towards SEA. Perhaps findings of this study may provide some information on the SEA education and further be incorporated in the syllabus.

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