scholarly journals Effects of gravitational lensing on neutrino oscillation in $$ \gamma $$-spacetime

2022 ◽  
Vol 82 (1) ◽  
Author(s):  
Hrishikesh Chakrabarty ◽  
Debasish Borah ◽  
Ahmadjon Abdujabbarov ◽  
Daniele Malafarina ◽  
Bobomurat Ahmedov
Keyword(s):  
Neutrino Oscillation ◽  
Gravitational Lensing ◽  
Neutrino Oscillations ◽  
Neutrino Masses ◽  
Axially Symmetric ◽  
Field Equations ◽  
Asymptotically Flat ◽  
Quantum Mechanical Treatment ◽  
Flat Solution ◽  
Best Fit

AbstractWe study the effects of gravitational lensing on neutrino oscillations in the $$\gamma $$ γ -spacetime which describes a static, axially-symmetric and asymptotically flat solution of the Einstein’s field equations in vacuum. Using the quantum-mechanical treatment for relativistic neutrinos, we calculate the phase of neutrino oscillations in this spacetime by considering both radial and non-radial propagation. We show the dependence of the oscillation probability on the absolute neutrino masses, which in the two-flavour case also depends upon the sign of mass squared difference, in sharp contrast with the well-known results of vacuum oscillation in flat spacetime. We also show the effects of the deformation parameter $$\gamma $$ γ on neutrino oscillations and reproduce previously known results for the Schwarzschild metric. We then extend these to a more realistic three flavours neutrino scenario and study the effects of the parameter $$\gamma $$ γ and the lightest neutrino mass while using best fit values of neutrino oscillation parameters.

scholarly journals Axially Symmetric, Asymptotically Flat Vacuum Metric with a Naked Singularity and Closed Timelike Curves

2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Debojit Sarma ◽  
Faizuddin Ahmed ◽  
Mahadev Patgiri
Keyword(s):  
Naked Singularity ◽  
Empty Space ◽  
Space Time ◽  
Axially Symmetric ◽  
Field Equations ◽  
Closed Timelike Curves ◽  
Asymptotically Flat ◽  
Type D ◽  
Initial Hypersurface ◽  
Petrov Classification

We present an axially symmetric, asymptotically flat empty space solution of the Einstein field equations containing a naked singularity. The space-time is regular everywhere except on the symmetry axis where it possesses a true curvature singularity. The space-time is of type D in the Petrov classification scheme and is locally isometric to the metrics of case IV in the Kinnersley classification of type D vacuum metrics. Additionally, the space-time also shows the evolution of closed timelike curves (CTCs) from an initial hypersurface free from CTCs.

scholarly journals Axially Symmetric Null Dust Space-Time, Naked Singularity, and Cosmic Time Machine

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Faizuddin Ahmed
Keyword(s):  
Gravitational Lensing ◽  
Cosmic Time ◽  
Naked Singularity ◽  
Space Time ◽  
Axially Symmetric ◽  
Time Machine ◽  
Einstein Field Equations ◽  
Field Equations ◽  
Closed Orbits ◽  
Group A

We present a gravitational collapse null dust solution of the Einstein field equations. The space-time is regular everywhere except on the symmetry axis where it possesses a naked curvature singularity and admits one parameter isometry group, a generator of axial symmetry along the cylinder which has closed orbits. The space-time admits closed timelike curves (CTCs) which develop at some particular moment in a causally well-behaved manner and may represent a Cosmic Time Machine. The radial geodesics near the singularity and the gravitational lensing (GL) will be discussed. The physical interpretation of this solution, based on the study of the equation of the geodesic deviation, will be presented. It was demonstrated that this solution depends on the local gravitational field consisting of two components with amplitudes Ψ2 and Ψ4.

U(1)B−L extension based on Δ(27) symmetry for lepton masses and mixings

2020 ◽  
Vol 35 (22) ◽  
pp. 2050181
Author(s):  
V. V. Vien ◽  
D. P. Khoi
Keyword(s):  
Standard Model ◽  
Neutrino Oscillation ◽  
The Other ◽  
Physical Parameters ◽  
Neutrino Masses ◽  
Type I ◽  
Seesaw Mechanism ◽  
Global Fit ◽  
Experimental Values ◽  
Best Fit

We propose a [Formula: see text] Standard Model (SM) extension based on [Formula: see text] symmetry in which neutrino mass orderings and the tiny neutrino masses are produced by the type-I seesaw mechanism. The obtained physical parameters are well consistent with the global fit of neutrino oscillation.1 The model is predictive in the sense that it reproduces the experimental values of neutrino parameters. Two of the predicted parameters have little deviations from the best-fit values given in Ref. 1, however they are consistent with the other experimental results.[Formula: see text]

NEUTRINO OSCILLATIONS: DISCOVERY, CURRENT STATUS, FUTURE DIRECTIONS

2009 ◽  
Vol 24 (18n19) ◽  
pp. 3437-3446 ◽  
Author(s):  
TAKAAKI KAJITA
Keyword(s):  
Neutrino Oscillation ◽  
Present Status ◽  
Neutrino Oscillations ◽  
Future Prospect ◽  
Current Status ◽  
Neutrino Masses ◽  
Future Directions ◽  
Mixing Angles ◽  
The Future

Neutrino oscillation was discovered about 10 years ago. Since then, the knowledge on neutrino masses and mixing angles have been improving substantially. This article describes neutrino oscillation experiments; the discovery, the present status and the future prospect.

scholarly journals FINALLY NEUTRINO HAS MASS

2000 ◽  
Vol 15 (05) ◽  
pp. 625-650 ◽  
Author(s):  
S. M. BILENKY ◽  
C. GIUNTI ◽  
C. W. KIM
Keyword(s):  
Neutrino Oscillation ◽  
Neutrino Mass ◽  
Solar Neutrino ◽  
Present Status ◽  
Neutrino Oscillations ◽  
Neutrino Masses ◽  
Atmospheric Neutrinos ◽  
Neutrino Experiments

The present status of the problem of neutrino mass, mixing and neutrino oscillations is briefly summarized. The evidence for oscillations of atmospheric neutrinos found recently in the Super-Kamiokande experiment is discussed. Indications in favor of neutrino oscillations obtained in solar neutrino experiments and in the accelerator LSND experiment are also considered. Implications of existing neutrino oscillation data for neutrino masses and mixing are discussed.

scholarly journals NEUTRINO OSCILLATIONS AND FLAVOR STRUCTURE OF SUPERSYMMETRY WITHOUT R-PARITY

1999 ◽  
Vol 14 (14) ◽  
pp. 903-911 ◽  
Author(s):  
OTTO C. W. KONG
Keyword(s):  
Neutrino Oscillation ◽  
Parity Violation ◽  
Neutrino Oscillations ◽  
Tree Level ◽  
Neutrino Masses ◽  
Simple Consequence ◽  
Flavor Structure ◽  
Consistent Treatment

Focusing on a simple three neutrino oscillation scenario motivated by the recent super-Kamiokande result, we discuss both tree-level and one-loop contributions to neutrino masses in supersymmetry without R-parity, aiming at discerning the flavor structure issues of the theory. The single-vev parametrization framework, which allows the first consistent treatment of the bilinear and trilinear R-parity violating terms, and hence the tree and one-loop contributions, without any assumption on the nature of R-parity violation. Though the very small neutrino masses imply stringent suppressions of the relevant R-parity violating couplings, we show that there is still room for understanding the suppressions as a simple consequence of the general flavor hierarchy.

Search for direct and indirect unitarity violation in neutrino oscillation experiments

2014 ◽  
Vol 29 (21) ◽  
pp. 1444006 ◽  
Author(s):  
Shu Luo
Keyword(s):  
Neutrino Oscillation ◽  
Neutrino Oscillations ◽  
Sterile Neutrino ◽  
Neutrino Masses ◽  
Sterile Neutrinos ◽  
The Difference

If three standard neutrinos mix with other degree of freedoms like sterile neutrinos, no matter how heavy the sterile neutrino masses are, it could result in the unitarity violation in the MNSP matrix. Nevertheless, the unitarity violation induced by the existence of light or heavy sterile neutrinos can have very different effects on neutrino oscillations, we call the former case direct unitarity violation and the later case the indirect unitarity violation. We will explain in this paper the difference of these two kinds of unitarity violations, then focus on the possibilities of searching the unitarity violation in neutrino oscillation experiments, of which the precision reactor experiments with multiple baselines are discussed in detail.

scholarly journals The Axially Symmetric Stationary Vacuum Field Equations in Einstein's Theory of General Relativity

1978 ◽  
Vol 31 (5) ◽  
pp. 427 ◽  
Author(s):  
A Sloane
Keyword(s):  
General Relativity ◽  
Exact Solutions ◽  
Vacuum Field ◽  
Stationary Case ◽  
Axially Symmetric ◽  
Field Equations ◽  
Asymptotically Flat ◽  
Stationary Vacuum ◽  
Flat Metric

All formulations of Einstein's vacuum field equations for which exact solutions have been found in the axially symmetric stationary case are compared, and the inherent restrictions of each are displayed. A measure of their usefulness as theoretical tools is gained by the ease with which they admit Kerr's (1963) solution (it being the simplest asymptotically flat metric of this kind). The solutions found using each formulation are listed and, where possible, suitably classified.

scholarly journals Traversable wormholes in Einsteinian cubic gravity

2019 ◽  
Vol 35 (06) ◽  
pp. 2050017 ◽  
Author(s):  
Mohammad Reza Mehdizadeh ◽  
Amir Hadi Ziaie
Keyword(s):  
Equation Of State ◽  
Gravitational Lensing ◽  
Energy Condition ◽  
Higher Order ◽  
Energy Conditions ◽  
Geodesic Motion ◽  
De Sitter ◽  
Asymptotically Flat ◽  
Traversable Wormholes ◽  
Standard Energy

In this work, we investigate wormhole configurations described by a constant redshift function in Einstein-Cubic gravity ( ECG ). We derive analytical wormhole geometries by assuming a particular equation of state ( EoS ) and investigate the possibility that these solutions satisfy the standard energy conditions. We introduce exact asymptotically flat and anti-de Sitter (AdS) spacetimes that admit traversable wormholes. These solutions are obtained by imposing suitable values for the parameters of the theory so that the resulted geometries satisfy the weak energy condition ( WEC ) in the vicinity of the throat, due to the presence of higher-order curvature terms. Moreover, we find that AdS solutions satisfy the WEC throughout the spacetime. A description of the geodesic motion of time-like and null particles is presented for the obtained wormhole solutions. Also, using gravitational lensing effects, observational features of the wormhole structure are discussed.

NEUTRINO MASSES, OSCILLATIONS, AND TESTS WITH FUTURE SUPERBEAMS AND A NEUTRINO FACTORY

2003 ◽  
Vol 18 (22) ◽  
pp. 3921-3933 ◽  
Author(s):  
M. LINDNER
Keyword(s):  
Cp Violation ◽  
Neutrino Oscillation ◽  
Neutrino Masses ◽  
Neutrino Factory ◽  
Mixing Angles ◽  
Long Baseline

Future long baseline neutrino oscillation (LBL) setups are discussed and the remarkable potential for very precise measurements of mass splittings, mixing angles, MSW effects, the sign of Δm2 and leptonic CP violation is shown. Furthermore we discuss the sensitivity improvements which can be obatined by combining the planned JHF-Superkamiokande and the proposed NuMI off-axis experiment.

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