Double Covering of Diffeomorphisms for Superstrings in Generic Curved Space

1986 ◽  
pp. 381-391
Author(s):  
Yuval Ne’eman ◽  
Djordje Šijački
Keyword(s):  
Double Covering ◽  
Curved Space

$\overline{\rm GL}(4, {\bf R})$ GROUP-TOPOLOGY, COVARIANCE AND CURVED-SPACE SPINORS

1987 ◽  
Vol 02 (05) ◽  
pp. 1655-1668 ◽  
Author(s):  
YUVAL NE’EMAN ◽  
DJORDJE ŠIJAČKI
Keyword(s):  
Hilbert Space ◽  
Double Covering ◽  
Group Topology ◽  
Diffeomorphism Groups ◽  
Curved Space ◽  
Spinor Fields ◽  
Finite Dimensional ◽  
Inner Automorphism ◽  
Infinite Component ◽  
Component Spinor

The existence of a topological double-covering for the GL (n, R) and diffeomorphism groups is proven. These groups do not have finite-dimensional faithful representations. Common mistakes in the literature are corrected. A theorem concerning an [Formula: see text] inner automorphism is proven, allowing for the construction of the corresponding infinite-component spinor fields. The effect of covariance on the Hilbert space is explained.

DISORDER AS PROJECTION FROM IDEAL, CURVED SPACE

1985 ◽  
Vol 46 (C8) ◽  
pp. C8-409-C8-413
Author(s):  
N. Rivier ◽  
A. Lawrence
Keyword(s):  
Curved Space

GRAVITY CAN BE OBSERVED IN THE ABSENCE OF CURVED SPACETIME, THUS CURVED SPACETIME IS NOT RESPONCIBLE FOR GRAVITY

2015 ◽  
Vol 8 (1) ◽  
pp. 1976-1981
Author(s):  
Casey McMahon
Keyword(s):  
General Relativity ◽  
Special Relativity ◽  
Relative Position ◽  
Gravitational Force ◽  
Curved Spacetime ◽  
Relative Time ◽  
Curved Space ◽  
Spacetime Curvature ◽  
Equivalence Model ◽  
The Universe

The principle postulate of general relativity appears to be that curved space or curved spacetime is gravitational, in that mass curves the spacetime around it, and that this curved spacetime acts on mass in a manner we call gravity. Here, I use the theory of special relativity to show that curved spacetime can be non-gravitational, by showing that curve-linear space or curved spacetime can be observed without exerting a gravitational force on mass to induce motion- as well as showing gravity can be observed without spacetime curvature. This is done using the principles of special relativity in accordance with Einstein to satisfy the reader, using a gravitational equivalence model. Curved spacetime may appear to affect the apparent relative position and dimensions of a mass, as well as the relative time experienced by a mass, but it does not exert gravitational force (gravity) on mass. Thus, this paper explains why there appears to be more gravity in the universe than mass to account for it, because gravity is not the resultant of the curvature of spacetime on mass, thus the “dark matter” and “dark energy” we are looking for to explain this excess gravity doesn’t exist.

Path integrals and the solution of the Schwinger model in curved space-time

1986 ◽  
Vol 33 (8) ◽  
pp. 2262-2266 ◽  
Author(s):  
J. Barcelos-Neto ◽  
Ashok Das
Keyword(s):  
Path Integrals ◽  
Space Time ◽  
Curved Space ◽  
Schwinger Model

Double cover K3 surfaces of Hirzebruch surfaces

2021 ◽  
Vol 21 (2) ◽  
pp. 221-225
Author(s):  
Taro Hayashi
Keyword(s):  
Rational Surface ◽  
K3 Surfaces ◽  
Double Cover ◽  
Double Covering ◽  
Smooth Surfaces ◽  
Branch Locus ◽  
Hirzebruch Surfaces ◽  
Double Covers

Abstract General K3 surfaces obtained as double covers of the n-th Hirzebruch surfaces with n = 0, 1, 4 are not double covers of other smooth surfaces. We give a criterion for such a K3 surface to be a double covering of another smooth rational surface based on the branch locus of double covers and fibre spaces of Hirzebruch surfaces.

Asymptotic behavior of the effective potential of composite fields in a curved space-time

1988 ◽  
Vol 31 (2) ◽  
pp. 163-167
Author(s):  
I. L. Bukhbinder ◽  
S. D. Odintsov
Keyword(s):  
Asymptotic Behavior ◽  
Effective Potential ◽  
Space Time ◽  
Curved Space

scholarly journals Linear and non-linear refractive indices in curved space

2021 ◽  
Vol 1796 (1) ◽  
pp. 012125
Author(s):  
Miftachul Hadi ◽  
Utama Alan Deta ◽  
Andri Sofyan Husein
Keyword(s):  
Refractive Indices ◽  
Curved Space ◽  
Non Linear

scholarly journals Searching for energy-resolved quasi-periodic oscillations in AGN

2021 ◽  
Author(s):  
Dominic I Ashton ◽  
Matthew J Middleton
Keyword(s):  
Power Law ◽  
Spectral Component ◽  
Broad Band ◽  
Initial Study ◽  
Periodic Oscillations ◽  
Single Observation ◽  
Curved Space ◽  
Multiple Observations ◽  
Band Noise ◽  
The Impact

Abstract X-ray quasi-periodic oscillations (QPOs) in AGN allow us to probe and understand the nature of accretion in highly curved space-time, yet the most robust form of detection (i.e. repeat detections over multiple observations) has been limited to a single source to-date, with only tentative claims of single observation detections in several others. The association of those established AGN QPOs with a specific spectral component has motivated us to search the XMM-Newton archive and analyse the energy-resolved lightcurves of 38 bright AGN. We apply a conservative false alarm testing routine folding in the uncertainty and covariance of the underlying broad-band noise. We also explore the impact of red-noise leak and the assumption of various different forms (power-law, broken power-law and lorentzians) for the underlying broad-band noise. In this initial study, we report QPO candidates in 6 AGN (7 including one tentative detection in MRK 766) from our sample of 38, which tend to be found at characteristic energies and, in four cases, at the same frequency across at least two observations, indicating they are highly unlikely to be spurious in nature.

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