Biehs, Svend-AgeSvend-AgeBiehsLang, SlawaSlawaLangPetrov, Alexander Yu.Alexander Yu.PetrovEich, ManfredManfredEichBen-Abdallah, PhilippePhilippeBen-Abdallah2020-07-222020-07-222015-10-22Physical review letters 115 (17): 174301 (2015)http://hdl.handle.net/11420/6888The blackbody theory is revisited in the case of thermal electromagnetic fields inside uniaxial anisotropic media in thermal equilibrium with a heat bath. When these media are hyperbolic, we show that the spectral energy density of these fields radically differs from that predicted by Planck's blackbody theory. We demonstrate that the maximum of their spectral energy density is shifted towards frequencies smaller than Wien's frequency making these media apparently colder. Finally, we derive Stefan-Boltzmann's law for hyperbolic media which becomes a quadratic function of the heat bath temperature.en1079-7114Physical review letters20151715American Physical Society (APS)http://rightsstatements.org/vocab/InC/1.0/PhysikBlackbody theory for hyperbolic materialsJournal Article10.15480/882.421410.1103/PhysRevLett.115.17430110.15480/882.4214To cite this version: Svend-Age Biehs, Slawa Lang, Alexander Yu. Petrov, Manfred Eich, and Philippe Ben-Abdallah. Blackbody Theory for Hyperbolic Materials. Physical Review Letters, American Physical Society, 2019, 115 (17), pp. 174301. 10.1103/PhysRevLett.115.174301 1Journal Article