We investigate pressure-induced superconductivity in the electride compound Li5C and in elemental $$\omega $$ -Hf using density functional theory (DFT) combined with Migdal–Eliashberg theory. Despite their distinct chemistry, both systems become superconducting under compression and share a key ingredient: an electride state in which interstitial anionic electrons organize into a two-dimensional kagome topology embedded in the ionic lattice. Li5C has been proposed as a kagome-electride superconductor in the pressure range 50 GPa 210 GPa, reaching a maximum transition temperature of $$T_{\mathrm c}= {48.3}~\text {K}$$ at 210 GPa, whereas pure Hf develops electride character in the 40 GPa 60 GPa regime of the high-pressure $$\omega $$ phase. Motivated by these developments, we first revisit Li5C and emphasize the importance of the electride state for its superconducting response. We then identify analogous kagome-electride features in $$\omega $$ -Hf and analyze their role in the superconductivity of compressed Hf. For $$\omega $$ -Hf, we show that spin–orbit coupling (SOC), which is significant in this d-band transition metal, acts in concert with electride-derived states near the Fermi level to enhance the electron–phonon coupling. This interplay provides a consistent microscopic picture of the superconducting phase and yields transition temperatures in very good agreement with previously reported experimental data.

In this work, we analyze a quantized cosmological model within the framework of Einstein-Aether theory, with matter content described by a cosmic string fluid and the presence of a negative cosmological constant. The quantization is performed using the minisuperspace formalism with a perfect fluid via the velocity potentials approach, which allows for the interpretation of the fluid-associated variable as an internal time. The resulting Wheeler-DeWitt equation is solved, yielding normalizable eigenstates and associated wave packets. Employing both the many-worlds and the de Broglie-Bohm interpretations, we determine the dynamics of the scale factor and the behavior of the quantum potential. The results demonstrate the absence of singularities in our model, and the independence of the probability density with respect to the spatial curvature.

Abstract This work investigates the influence of Nb 2 O 5 incorporation on the structural and luminescent properties of Eu 3+ –doped phosphate glasses. Raman spectroscopy revealed that the addition of Nb 2 O 5 promotes the substitution of PO 4 units by NbO 6 octahedra, leading to depolymerization of the glass network and a reduction in phonon energy. Optical absorption spectra showed a redshift in the absorption edge and a decrease in the optical band gap, associated with an increased number of nonbonding oxygens. Photoluminescence spectra exhibited an enhancement in the hypersensitive 5 D 0 → 7 F 2 transition and increases in both the relative intensity ratio ( R ) and the Judd–Ofelt parameter Ω 2 , indicating a rise in local asymmetry. Lifetime measurements revealed a reduction in the experimental lifetime, along with an increase in total radiative emission rate and suppression of non–radiative processes, yielding a quantum efficiency of up to 93%. These findings demonstrate that Nb 2 O 5 incorporation significantly improves the red emission efficiency of Eu 3+ ions in phosphate glass matrices.