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We show analytically that the vacuum electromagnetic stress-energy tensor outside a ball with constant dielectric constant and permeability always obeys the weak, null, dominant, and strong energy conditions. There are still no known examples in quantum field theory in which the averaged null energy condition in flat spacetime is violated.
Energy conditions for matter fields are comprehensively investigated in arbitrary $n(ge 3)$ dimensions without specifying future and past directions locally. We classify an energy-momentum tensor into $n$-dimensional counterparts of the Hawking-Ellis
A complete theory of gravity impels us to go beyond Einsteins General Relativity. One promising approach lies in a new class of teleparallel theory of gravity named $f(Q)$, where the nonmetricity $Q$ is responsible for the gravitational interaction.
The recently proposed $f(Q, T)$ gravity (Xu et al. Eur. Phys. J. C textbf{79} (2019) 708) is an extension of the symmetric teleparallel gravity. The gravitational action $L$ is given by an arbitrary function $f$ of the non-metricity $Q$ and the trace
We present a simple static spacetime which describes a spherically symmetric traversable wormhole characterized by a length parameter $l$ and reduces to Minkowski in the limit $lto 0$. The wormhole connects two distinct asymptotically flat regions wi
We are living in a golden age for experimental cosmology. New experiments with high accuracy precision are been used to constrain proposals of several theories of gravity, as it has been never done before. However, important roles to constrain new th