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Wikipedia gives that maxwell tensor components have minus in the electromagnetic stress energy tensor https://en.wikipedia.org/wiki/Electromagnetic_stress%E2%80%93energy_tensor. That mean the electromagnetic field has negative pressure alike to dark energy?

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It is a tensor, so the exerted forces depend on direction. The field lines have an effective tension, while at the same exerting a sideways outward positive pressure.

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The stress-energy tensor for the electromagnetic field is derived from the electromagnetic field tensor, which is antisymmetric. The presence of minus signs in the stress-energy tensor components reflects the fact that energy and momentum densities associated with the electromagnetic field can contribute with signs opposite to what one might expect from, say, a perfect fluid.

However, this doesn't mean that the pressure is negative in the usual sense. In the case of dark energy, negative pressure is invoked to explain the observed accelerated expansion of the universe. In the case of electromagnetic fields, the negative signs in the stress-energy tensor components are a result of the mathematical structure and conventions used in the theory rather than an indication of negative pressure in the traditional sense.

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