8,063 research outputs found
Noncommutative Black Holes and the Singularity Problem
A phase-space noncommutativity in the context of a Kantowski-Sachs
cosmological model is considered to study the interior of a Schwarzschild black
hole. Due to the divergence of the probability of finding the black hole at the
singularity from a canonical noncommutativity, one considers a non-canonical
noncommutativity. It is shown that this more involved type of noncommutativity
removes the problem of the singularity in a Schwarzschild black hole.Comment: Based on a talk by CB at ERE2010, Granada, Spain, 6th-10th September
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Entropic Gravity, Phase-Space Noncommutativity and the Equivalence Principle
We generalize E. Verlinde's entropic gravity reasoning to a phase-space
noncommutativity set-up. This allow us to impose a bound on the product of the
noncommutative parameters based on the Equivalence Principle. The key feature
of our analysis is an effective Planck's constant that naturally arises when
accounting for the noncommutative features of the phase-space.Comment: 12 pages. Version to appear at the Classical and Quantum Gravit
An experience with Desmos in the study of the quadratic function
In this paper we present a didactic experience in the subject of Mathematics carried out in a distance
learning context, on the topic Quadratic Function, using the digital and free platform Desmos. The use
of this tool was determinant for the teaching and learning of quadratic function since its teaching took
place in distance education, due to the pandemic situation.
In a pandemic context, the use of tools to gauge student learning was a necessity, but practices such
as the one described in this paper should be incorporated into a normal classroom environment,
promoting discovery through graphical and algebraic manipulation.publishe
Deformation quantization of noncommutative quantum mechanics and dissipation
We review the main features of the Weyl-Wigner formulation of noncommutative
quantum mechanics. In particular, we present a -product and a Moyal
bracket suitable for this theory as well as the concept of noncommutative
Wigner function. The properties of these quasi-distributions are discussed as
well as their relation to the sets of ordinary Wigner functions and positive
Liouville probability densities. Based on these notions we propose criteria for
assessing whether a commutative regime has emerged in the realm of
noncommutative quantum mechanics. To induce this noncommutative-commutative
transition, we couple a particle to an external bath of oscillators. The master
equation for the Brownian particle is deduced.Comment: 7 pages, Latex file, Based on a talk presented by Joao Prata at
D.I.C.E. 2006, Piombino, Ital
Implementation and Performance Analysis of a Low Resolution OFDM System Prototype With Low Cost Hardware
The present work focus on the implementation and analyze of performance of a
low-resolution OFDM system prototype with low-cost hardware. A software defined
radio (SDR) system was chosen in this implementation due to its various
advantages over a traditional radio system. Among the options of SDR devices
available, the use of universal software radio peripherals (USRP) was avoided
due to its high cost, despite its popularity in this field of research.
Alternatively, a combination of two low-cost SDRs, "Hackrf One" and "RTL- SDR
Blog V3" with the GNU Radio, a popular, free and open source radio software,
were used. Thus, it was possible to emulate the behavior of a low resolution
ADC in the receiver, characterize its performance and estimate its energy
savings. This allowed us to determine the feasibility of building a component
with the analog-to-digital conversion function with few bits of resolution. We
conclude that the performance of an ADC with at least 5 bits of resolution is
pretty reasonable and that this reduction in the number of bits, in comparison
to 8-bit ADC, represents a fairly expressive energy saving
Effect of delipidant agents during in vitro culture on the development, lipid content, gene expression, and cryotolerance of bovine embryos.
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