Is the speed of gravitational waves non- dispersive?

In summary, the speed of gravitational waves has been proven to be non-dispersive through observations in LIGO detections. This is because the signals received from two black holes spiraling towards each other show no frequency distortion, indicating that all frequencies travel with the same speed. This is further supported by the fact that even over long distances and time periods, no frequency dispersion is seen.
  • #1
shadishacker
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Dear all,
In a recent talk, I have heard that speed of gravitational waves is non-dispersive.
How is it proved "observationally" in LIGO detections that all the frequencies travel with the same speed, so one can say the speed is non-dispersive?
 
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  • #2
If you received a gravitational signal that followed a sine wave slowly increasing in amplitude and then slowly decaying, then as far as frequency dispersion is concerned, there would little you could conclude from it. That is because such a wave would have little more than a single frequency component - so there would be nothing to disperse.

On the other hand, if you are watching two black holes spiraling towards each other, frequency dispersion would distort the signal. For example, the higher frequency components would arrive first followed by lower and lower frequency components. Since what they "hear" of these gravitational waves is what they would expect from the phenomenon that created them, the observations show no frequency distortion. Since the source of these wave is many light years away, and not distortion is seen ever across time periods of several milliseconds, an upper limit can be placed on the amount of frequency dispersion.
 
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1. What are gravitational waves?

Gravitational waves are ripples in the fabric of spacetime that are created by massive objects accelerating. They were first predicted by Albert Einstein's theory of general relativity.

2. How do gravitational waves travel?

Gravitational waves travel at the speed of light, meaning they move at approximately 186,000 miles per second.

3. Is the speed of gravitational waves non-dispersive?

Yes, according to current scientific understanding, the speed of gravitational waves is non-dispersive. This means that regardless of their frequency or energy, gravitational waves travel at the same speed.

4. Why is it important to know if the speed gravitational waves is non-dispersive?

Knowing the speed of gravitational waves and whether or not it is non-dispersive is important for understanding the behavior of these waves and their potential applications in the future. It also helps to confirm the accuracy of theories, such as Einstein's theory of general relativity.

5. How is the speed of gravitational waves measured?

The speed of gravitational waves is typically measured using large-scale experiments, such as the Laser Interferometer Gravitational-Wave Observatory (LIGO). These experiments use lasers and mirrors to detect the distortions in spacetime caused by passing gravitational waves, allowing scientists to calculate their speed.

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