Gravitational waves may oscillate

[beecee]

https://phys.org/news/2017-09-gravitational-oscillate-neutrinos.html

Gravitational waves may oscillate, just like neutrinos:

(Phys.org)—Using data from the first-ever gravitational waves detected last year, along with a theoretical analysis, physicists have shown that gravitational waves may oscillate between two different forms called "g" and "f"-type gravitational waves. The physicists explain that this phenomenon is analogous to the way that neutrinos oscillate between three distinct flavors—electron, muon, and tau. The oscillating gravitational waves arise in a modified theory of gravity called bimetric gravity, or "bigravity," and the physicists show that the oscillations may be detectable in future experiments.

The researchers, Kevin Max, a PhD student at Scuola Normale Superiore di Pisa and INFN Pisa, Italy; Moritz Platscher, a PhD student at the Max Planck Institute for Nuclear Physics, Germany; and Juri Smirnov, a postdoc at the University of Florence, Italy, have published a paper on their analysis of gravitational wave oscillations in a recent issue of Physical Review Letters.

As the physicists explain, the work may help answer the question of what "the other 95%" of the universe is made of, by suggesting that the answer may lie in modifications to gravity rather than new particles.


Read more at: https://phys.org/news/2017-09-gravitational-oscillate-neutrinos.html#jCp

https://arxiv.org/pdf/1703.07785.pdf

Gravitational Wave Oscillations in Bigravity: 

ABSTRACT

We derive consistent equations for gravitational wave oscillations in bigravity. In this framework a second dynamical tensor field is introduced in addition to General Relativity and coupled such that one massless and one massive linear combination arise. Only one of the two tensors is the physical metric coupling to matter, and thus the basis in which gravitational waves propagate is different from the basis where the wave is produced and detected. Therefore, one should expect – in analogy to neutrino oscillations – to observe an oscillatory behavior. We show how this behavior arises explicitly, discuss phenomenological implications and present new limits on the graviton parameter space in bigravity.

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Anyone care to elaborate on the above possibilities and consequences?

Edited September 21, 2017 by beecee

[interested]

20 hours ago, beecee said:

https://phys.org/news/2017-09-gravitational-oscillate-neutrinos.html

Gravitational waves may oscillate, just like neutrinos:

(Phys.org)—Using data from the first-ever gravitational waves detected last year, along with a theoretical analysis, physicists have shown that gravitational waves may oscillate between two different forms called "g" and "f"-type gravitational waves. The physicists explain that this phenomenon is analogous to the way that neutrinos oscillate between three distinct flavors—electron, muon, and tau. The oscillating gravitational waves arise in a modified theory of gravity called bimetric gravity, or "bigravity," and the physicists show that the oscillations may be detectable in future experiments.

The researchers, Kevin Max, a PhD student at Scuola Normale Superiore di Pisa and INFN Pisa, Italy; Moritz Platscher, a PhD student at the Max Planck Institute for Nuclear Physics, Germany; and Juri Smirnov, a postdoc at the University of Florence, Italy, have published a paper on their analysis of gravitational wave oscillations in a recent issue of Physical Review Letters.

As the physicists explain, the work may help answer the question of what "the other 95%" of the universe is made of, by suggesting that the answer may lie in modifications to gravity rather than new particles.


Read more at: https://phys.org/news/2017-09-gravitational-oscillate-neutrinos.html#jCp

https://arxiv.org/pdf/1703.07785.pdf

Gravitational Wave Oscillations in Bigravity: 

ABSTRACT

We derive consistent equations for gravitational wave oscillations in bigravity. In this framework a second dynamical tensor field is introduced in addition to General Relativity and coupled such that one massless and one massive linear combination arise. Only one of the two tensors is the physical metric coupling to matter, and thus the basis in which gravitational waves propagate is different from the basis where the wave is produced and detected. Therefore, one should expect – in analogy to neutrino oscillations – to observe an oscillatory behavior. We show how this behavior arises explicitly, discuss phenomenological implications and present new limits on the graviton parameter space in bigravity.

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Anyone care to elaborate on the above possibilities and consequences?

Maybe existing theories are just good approximations like Newtons theories before Einstein came along. Maybe the concept of dark energy and dark matter in various new models are obsolete. The theories presented in the link are at this stage in the early days but look interesting.