An Extended Framework For Overcoming The Radiation Pressure Barrier: The Anisotropic Disk-Radiation-Diffusion (Adrd) Model

Publication Details

Publication Date

10/09/2026

Volume / Issue

Vol 1, Issue 4 (2026)

Article No.

001

Journal

British Journal of Contemporary Research

DOI

https://doi.org/10.67693/BJCR-9JNM4CDL

Received

16 Jul 2026

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8

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Abstract

The formation of massive stars (MSs) is fundamentally limited by the radiation pressure barrier, where radiative force on dust grains typically exceeds gravitational pull, halting accretion at approximately 10 in spherical symmetry. This paper proposes a unified, multi-regime mechanism - the Anisotropic Disk-Radiation-Diffusion (ADRD) model - to explain how MSs overcome this limit through a coupled feedback process. We derive a single, dimensionless effective Eddington criterion, , incorporating four critical physical corrections: (1) anisotropic flux distribution based on flared disk geometry, (2) directional dust opacity coupled to a non-spherical sublimation front, (3) a modified flux limiter that interpolates between Rosseland diffusion and free-streaming regimes, and (4) convective dilution of the radiative gradient. We show that radiation is channeled through polar energy vents, while accretion proceeds through a "dusty corridor" in the equatorial midplane, where a factor geometrically reduces the radial component of radiation force Using a 1D analytical grid to simulate steady-state accretion (10-3 yr-1), we find that while the spherical Eddington ratio exceeds 50 for an 80star, the ADRD effective ratio remains well below unity in the opaque disk midplane. The primary bottleneck occurs at the dust sublimation front. Our numerical iterations identify a critical mass limit of approximately 49 under standard interstellar conditions—a five-fold increase over the classical spherical limit. We provide a predictive scaling law,, offering a testable framework for future 3D radiation-hydrodynamic simulations. This model demonstrates that the radiation barrier is not a hard limit but a geometric and hydrodynamic filter that can be bypassed by structured, non-radial accretion flows.

License

This article is published under the Creative Commons Attribution 4.0 International License . Free to read, share, and adapt with attribution.