Does Special Relativity Offer a Continuity Equation for Energy Conservation?

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SUMMARY

The discussion centers on the existence of an energy continuity equation within the framework of special relativity, specifically involving the stress-energy tensor, denoted as T^{\mu\nu}. The continuity equation, expressed as \nabla_{\nu}T^{\mu\nu}=0, illustrates the conservation of energy and momentum in both curved and flat spacetime. The conversation highlights the importance of this equation in understanding energy conservation before delving into general relativity, where energy definitions become more complex. The validity of the equation in special relativity is acknowledged to be case-dependent until the application of the Einstein equation and the Bianchi identity.

PREREQUISITES
  • Understanding of special relativity principles
  • Familiarity with the stress-energy tensor (T^{\mu\nu})
  • Knowledge of continuity equations in physics
  • Basic grasp of general relativity concepts
NEXT STEPS
  • Study the implications of the Bianchi identity in general relativity
  • Explore the role of the stress-energy tensor in various physical scenarios
  • Investigate the differences between energy conservation in special and general relativity
  • Learn about the Einstein field equations and their applications
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Physicists, students of theoretical physics, and anyone interested in the mathematical foundations of energy conservation in relativity.

Phrak
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Is there such an animal as an energy continuity equation, or one involving Pmu or the stress energy tensor?

It suddenly stuck me that if we are to be so inclined by theory as we are by empirical evidence that energy is a conserved quantity, then there should be an equation that describes it in four dimensions.

Rather than bring in general relativity all at once where energy is not well defined (I have reservations), the stress energy tensor is still a tensor in special relativity, and so special relativity might be the better place to start.
 
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Yes, the continuity equation:
\nabla_{\nu}T^{\mu\nu}=0

This expresses the conservation of energy and momentum locally in curved spacetime and globally in flat spacetime.
 
DaleSpam said:
Yes, the continuity equation:
\nabla_{\nu}T^{\mu\nu}=0

This expresses the conservation of energy and momentum locally in curved spacetime and globally in flat spacetime.

Thanks, I should have done some research sooner. It seems, at this point the validity of \nabla T = 0 in special relativity goes on a case by case basis, until the Einstein equation is invoked where the Bianchi identity is applied to the other side.
 

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