Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Physics
Does Entropic Gravity Bound The Masses Of The Photon And Graviton?, Jonas R. Mureika, R. B. Mann
Does Entropic Gravity Bound The Masses Of The Photon And Graviton?, Jonas R. Mureika, R. B. Mann
Physics Faculty Works
If the information transfer between test particle and holographic screen in entropic gravity respects both the uncertainty principle and causality, a lower limit on the number of bits in the universe relative to its mass may be derived. Furthermore, these limits indicate particles that putatively travel at the speed of light -- the photon and/or graviton -- have a non-zero mass m≥10−68 kg. This result is found to be in excellent agreement with current experimental mass bounds on the graviton and photon, suggesting that entropic gravity may be the result of a (recent) softly-broken local symmetry. Stronger bounds emerge …
Vector Unparticle Enhanced Black Holes: Exact Solutions And Thermodynamics, Jonas R. Mureika, Euro Spallucci
Vector Unparticle Enhanced Black Holes: Exact Solutions And Thermodynamics, Jonas R. Mureika, Euro Spallucci
Physics Faculty Works
Tensor and scalar unparticle couplings to matter have been shown to enhance gravitational interactions and provide corrections to the Schwarzschild metric and associated black hole structure. We derive an exact solution to the Einstein equations for vector unparticles, and conclusively demonstrate that these induce Riessner–Nordström (RN)-like solutions where the role of the “charge” is defined by a composite of unparticle phase space parameters. These black holes admit double-horizon structure, although unlike the RN metric these solutions have a minimum inner horizon value. In the extremal limit, the Hawking temperature is shown to vanish. As with the scalar/tensor case, the (outer) …
A Kinematical Approach To Conformal Cosmology, Gabriele U. Varieschi
A Kinematical Approach To Conformal Cosmology, Gabriele U. Varieschi
Physics Faculty Works
We present an alternative cosmology based on conformal gravity, as originally introduced by H. Weyl and recently revisited by P. Mannheim and D. Kazanas. Unlike past similar attempts our approach is a purely kinematical application of the conformal symmetry to the Universe, through a critical reanalysis of fundamental astrophysical observations, such as the cosmological redshift and others. As a result of this novel approach we obtain a closed-form expression for the cosmic scale factor R(t) and a revised interpretation of the space-time coordinates usually employed in cosmology. New fundamental cosmological parameters are introduced and evaluated. This emerging new cosmology does …
Intonation And Compensation Of Fretted String Instruments, Gabriele U. Varieschi, Christina M. Gower
Intonation And Compensation Of Fretted String Instruments, Gabriele U. Varieschi, Christina M. Gower
Physics Faculty Works
We discuss theoretical and physical models that are useful for analyzing the intonation of musical instruments such as guitars and mandolins and can be used to improve the tuning on these instruments. The placement of frets on the fingerboard is designed according to mathematical rules and the assumption of an ideal string. The analysis becomes more complicated when we include the effects of deformation of the string and inharmonicity due to other string characteristics. As a consequence, perfect intonation of all the notes on the instrument cannot be achieved, but complex compensation procedures can be introduced to minimize the problem. …