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We compare the known in literature, explicitly covariant 4-dimensionalformula for the symmetric energy-momentum tensor of electromagnetic field in amedium and the energy-momentum tensor derived by Abraham in the 3-dimensionalvector form. It is shown that these two objects coincide only on the physicalconfiguration space $\overline\Gamma$, formed by the field vectors and thevelocity of the medium, which satisfy the Minkowski constitutive relations. Itshould be emphasized that the 3-dimensional vector formulae for the componentsof the energy-momentum tensor were obtained by Abraham only on$\overline\Gamma$, and the task of their extension to the whole unconditionalconfiguration space $\Gamma$ was not posed. In order to accomplish thecomparison noted above we derive the covariant formula anew by another method,namely, by generalizing the Abraham reasoning. The comparison conducted enablesone to treat the explicitly covariant formula as a unique consistent extensionof the Abraham formulae to the whole configuration space $\Gamma$. Thus thequestion concerning the relativistic covariance of the original 3-dimensionalAbraham formulae defined on $\overline\Gamma$ is solved positively. We discussin detail the relativistic covariance of the 3-dimensional vector formulae forindividual components of the 4-dimensional tensors in electrodynamics which ismanifested in the form-invariance of these formulae under Lorentztransformations.

Symmetric energy-momentum tensor: The Abraham form and the explicitly covariant formula