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Physical Sciences and Mathematics Commons™

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Physics

Loyola Marymount University and Loyola Law School

2012

Articles 1 - 8 of 8

Full-Text Articles in Physical Sciences and Mathematics

Primordial Black Hole Evaporation And Spontaneous Dimensional Reduction, Jonas R. Mureika Sep 2012

Primordial Black Hole Evaporation And Spontaneous Dimensional Reduction, Jonas R. Mureika

Physics Faculty Works

Several different approaches to quantum gravity suggest the effective dimension of spacetime reduces from four to two near the Planck scale. In light of such evidence, this Letter re-examines the thermodynamics of primordial black holes (PBHs) in specific lower-dimensional gravitational models. Unlike in four dimensions, (1 + 1)-D black holes radiate with power P ∼ M2BH, while it is known no (2+1)-D (BTZ) black holes can exist in a non-anti-de Sitter universe. This has important relevance to the PBH population size and distribution, and consequently on cosmological evolution scenarios. The number of PBHs that have evaporated to …

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Simulating A Guitar With A Conventional Sonometer, Zily Burstein, Christina M. Gower, Gabriele U. Varieschi Jun 2012

Simulating A Guitar With A Conventional Sonometer, Zily Burstein, Christina M. Gower, Gabriele U. Varieschi

Physics Faculty Works

In this paper we present a simple way to convert a conventional sonometer into a simulated fretted instrument, such as a guitar or similar, by adding a fingerboard to the sonometer. In particular, we use this modified apparatus in relation to the problem of the instrument intonation, i.e., how to obtain correctly tuned notes on these string instruments. The experimental procedures presented in this study can become a more structured laboratory activity to be used in general physics courses or acoustics classes.

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Noncontact Ultrasound Imaging Applied To Cortical Bone Phantoms, John Bulman, K. S. Ganezer, P. W. Halcrow, Ian Neeson Jun 2012

Noncontact Ultrasound Imaging Applied To Cortical Bone Phantoms, John Bulman, K. S. Ganezer, P. W. Halcrow, Ian Neeson

Physics Faculty Works

Purpose: The purpose of this paper was to take the first steps toward applying noncontact ultrasound (NCU) to the tasks of monitoring osteoporosis and quantitative ultrasound imaging (QUS) of cortical bone. The authors also focused on the advantages of NCU, such as its lack of reliance on a technologist to apply transducers and a layer of acoustical coupling gel, the ability of the transducers to operate autonomously as specified by preprogrammed software, and the likely reduction in statistical and systematic errors associated with the variability in the pressure applied by the clinician to the transmitting transducer that NCU might provide. …

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Could Any Black Holes Be Produced At The Lhc?, Jonas R. Mureika, Piero Nicolini, Euro Spallucci Apr 2012

Could Any Black Holes Be Produced At The Lhc?, Jonas R. Mureika, Piero Nicolini, Euro Spallucci

Physics Faculty Works

We introduce analytical quantum gravity modifications of the production cross section for terascale black holes by employing an effective ultraviolet cut off l. We find the new cross sections approach the usual "black disk" form at high energy, while they differ significantly near the fundamental scale from the standard increase with respect to s. We show that the heretofore discontinuous step function used to represent the cross section threshold can realistically be modeled by two functions representing the incoming and final parton states in a high energy collision. The growth of the cross section with collision energy is …

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Conformal Cosmology And The Pioneer Anomaly, Gabriele U. Varieschi Jan 2012

Conformal Cosmology And The Pioneer Anomaly, Gabriele U. Varieschi

Physics Faculty Works

No abstract provided.

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The Double Cover Of The Real Symplectic Group And A Theme From Feynman’S Quantum Mechanics, Michael Berg Jan 2012

The Double Cover Of The Real Symplectic Group And A Theme From Feynman’S Quantum Mechanics, Michael Berg

Mathematics Faculty Works

We present a direct connection between the 2-cocycle defining the double cover of the real symplectic group and a Feynman path integral describing the time evolution of a quantum mechanical system.

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A New Topological Perspective On Quantization In Physics, Hooman Rahimizadeh, Stan Sholar, Michael Berg Jan 2012

A New Topological Perspective On Quantization In Physics, Hooman Rahimizadeh, Stan Sholar, Michael Berg

Mathematics Faculty Works

We propose a new characterization of classical quantization in physics in terms of sheaf cohomology on the site of spacetime as a smooth 4-manifold. The perspective of sheaf cohomology is motivated by a presentation of the Aharonov-Bohm effect in terms of the integration of differential forms.

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On Levi-Civita’S Alternating Symbol, Schouten’S Alternating Unit Tensors, Cpt, And Quantization, Evert Jan Post, Stan Sholar, Hooman Rahimizadeh, Michael Berg Jan 2012

On Levi-Civita’S Alternating Symbol, Schouten’S Alternating Unit Tensors, Cpt, And Quantization, Evert Jan Post, Stan Sholar, Hooman Rahimizadeh, Michael Berg

Mathematics Faculty Works

The purpose of the present article is to demonstrate that by adopting a unifying differential geometric perspective on certain themes in physics one reaps remarkable new dividends in both microscopic and macroscopic domains. By replacing algebraic objects by tensor-transforming objects and introducing methods from the theory of differentiable manifolds at a very fundamental level we obtain a Kottler-Cartan metric-independent general invariance of the Maxwell field, which in turn makes for a global quantum superstructure for Gauss-Amp`ere and Aharonov-Bohm “quantum integrals.” Beyond this, our approach shows that postulating a Riemannian metric at the quantum level is an unnecessary concept and our …

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