Results 71 to 80 of about 2,073,401 (194)

New Estimates of the Spin and Accretion Rate of the Black Hole M87*

open access: yesThe Astrophysical Journal Letters
In this Letter, we use the imaging results of M87* from the Event Horizon Telescope (EHT) to calculate the rotational velocity of the inner edge of the accretion disk and find a value of ∼0.14 c .
Michael Drew   +4 more
doaj   +1 more source

Non-extensive entropic corrected thermal stability and geometries of well-known black holes

open access: yesNuclear Physics B
In this study, we investigate the thermodynamic stability and geometries of well-known black holes such as the spherical static black hole, charged Einstein-Gauss-Bonnet black hole and R-N black hole of the dyadosphere in the presence of Barrow and Gauss-
Farzan Mushtaq   +5 more
doaj   +1 more source

Halide Composition Controls Phase Morphology and Device Specific Performance in Perovskite Photovoltaics and Light Emitting Diodes

open access: yesAdvanced Functional Materials, EarlyView.
We demonstrate that halide composition determines phase morphology, governing distinct operating mechanisms in mixed halide perovskites. Phase segregating 75% Br compositions enhance solar cell performance, whereas intrinsically phase‐separated 95% Br compositions provide stable light emitting diodes.
Tal Binyamin   +6 more
wiley   +1 more source

Microscopic Calabi-Yau Black Holes in String Theory [PDF]

open access: yes, 2011
In this thesis we study microscopic aspects of Calabi-Yau black holes in string theory. We compute the absorption cross-section of the space-time massless scalars by the world-volume of D2-branes, wrapped on the S2 of an AdS_2 x S^2 x CY_3 geometry of a ...
Ansari, Saeid
core   +1 more source

Gluing gravitational blocks for AdS black holes

open access: yesJournal of High Energy Physics, 2019
We provide a unifying entropy functional and an extremization principle for black holes and black strings in AdS4 × S 7 and AdS5 × S 5 with arbitrary rotation and generic electric and magnetic charges.
Seyed Morteza Hosseini   +2 more
doaj   +1 more source

Stabilization of Strongly Reduced Fe(I) Single Atom Species Coordinated in a 2D Self‐Assembled Metal–Organic Network

open access: yesAdvanced Functional Materials, EarlyView.
A graphene‐supported 2D metal–organic network stabilizes highly reactive Fe(I)‐N4 single sites through Co‐induced charge redistribution. Combined experiments and theory reveal Fe(I) formation, oxygen‐driven oxidation, and O2 activation mechanisms, offering a strategy to access low‐valent iron centers relevant to catalytic and biological processes ...
Alessandro Namar   +9 more
wiley   +1 more source

Action integrals for quantum BTZ black holes

open access: yesJournal of High Energy Physics
Black holes exactly incorporating quantum matter backreaction effects, namely, quantum black holes, are notoriously difficult to construct, let alone study their horizon thermodynamics.
Yuanfan Cao, Andrew Svesko
doaj   +1 more source

Unified Pressure and Field Response Across Distinct Charge‐Order Regimes in Ti‐Doped CsV3Sb5

open access: yesAdvanced Functional Materials, EarlyView.
We microscopically investigate the interplay between charge order and superconductivity in a kagome superconductor across regimes of long‐ and short‐range charge order. Hydrostatic‐pressure and magnetic‐field μSR$\mu{\rm SR}$ measurements reveal remarkably similar superconducting and normal‐state time‐reversal‐symmetry‐breaking responses in both ...
P. Kral   +12 more
wiley   +1 more source

Photon Shells, Black Hole Shadows, and Accretion Toroids

open access: yesThe Astrophysical Journal Supplement Series
We analyze the properties of the Kerr black hole (BH) photon shell, focusing on the influence of aggregates of corotating and counterrotating toroids (ringed accretion disks, hereafter RAD), orbiting in the BH photon shell (photon shell “obscuration ...
D. Pugliese, Z. Stuchlík
doaj   +1 more source

Defect‐Mediated Inelastic Light Scattering by Infrared Phonons in Hexagonal Boron Nitride

open access: yesAdvanced Functional Materials, EarlyView.
Optically active defects in hexagonal boron nitride enable inelastic stimulated light scattering mediated by infrared‐active phonons, relaxing conventional Raman selection rules. Defect engineering enhances the Stokes‐conversion process and activates both TO‐ and LO‐phonon scattering channels.
Prabhdeep Singh   +4 more
wiley   +1 more source

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