A Proposal for Testing Gravity's Rainbow

Various approaches to quantum gravity such as string theory, loop quantum gravity and Horava-Lifshitz gravity predict modifications of the energy-momentum dispersion relation. Magueijo and Smolin incorporated the modified dispersion relation (MDR) with the general theory of relativity to yield a theory of gravity's rainbow. In this paper, we investigate the Schwarzschild metric in the context of gravity's rainbow. We investigate rainbow functions from three known modified dispersion relations that were introduced by Amelino-Camelia, et el. in [arXiv:hep-th/9605211, arXiv:0806.0339v2, arXiv:astro-ph/9712103] and by Magueijo-Smolin in [arXiv:hep-th/0112090]. We study the effect of the rainbow functions on the deflection of light, photon time delay, gravitational red-shift, and the weak equivalence principle. We compare our results with experiments to obtain upper bounds on the parameters of the rainbow functions.Comment: 6 pages, no figures, to appear in Europhysics Letter

Sensorless action-reaction-based residual vibration suppression for multi-degree-of-freedom flexible systems

This paper demonstrates the feasibility of controlling motion and vibration of a class of flexible systems with inaccessible or unknown outputs through measurements taken from their actuators which are used as single platforms for measurements, whereas flexible dynamical systems are kept free from any attached sensors. Based on the action reaction law of dynamics, the well-known disturbance observer is used to determine the incident reaction forces from these dynamical systems on the interface planes with their actuators. Reaction forces are considered as feedback-like signals that can be used as alternatives to the inaccessible system outputs. The sensorless action reaction based motion and vibration control technique is implemented on a flexible system with finite modes and all results are verified experimentally

Black Hole with Quantum Potential

In this work, we investigate black hole (BH) physics in the context of quantum corrections. These quantum corrections were introduced recently by replacing classical geodesics with quantal (Bohmian) trajectories and hence form a quantum Raychaudhuri equation (QRE). From the QRE, we derive a modified Schwarzschild metric, and use that metric to investigate BH singularity and thermodynamics. We find that these quantum corrections change the picture of Hawking radiation greatly when the size of BH approaches the Planck scale. They prevent the BH from total evaporation, predicting the existence of a quantum BH remnant, which may introduce a possible resolution for the catastrophic behavior of Hawking radiation as the BH mass approaches zero. Those corrections also turn the spacelike singularity of the black hole to be timelike, and hence this may ameliorate the information loss problem.Comment: 16 pages, 6 figures; Accepted in Nucl.Phys.

Time Crystals from Minimum Time Uncertainty

Motivated by the Generalized Uncertainty Principle, covariance, and a minimum measurable time, we propose a deformation of the Heisenberg algebra and show that this leads to corrections to all quantum mechanical systems. We also demonstrate that such a deformation implies a discrete spectrum for time. In other words, time behaves like a crystal. As an application of our formalism, we analyze the effect of such a deformation on the rate of spontaneous emission in a hydrogen atom.Comment: 11 pages, to appear in Eur. Phys. J.

Going Green: Experimental Adaptation of Scenedesmus Dimorphus to Marine Conditions

Algae has gained some interest as the need for alternative fuels becomes more pressing. Reliance on fossil fuels is causing our environment and economy harm, and is not sustainable moving forward. Lipid rich algae strains can be used in the production of biofuels, and provide an alternative fuel source. One challenge facing the prospect of algae as a fuel source is that lipid rich algae grows exclusively in freshwater. Considering the scarcity and cost to use freshwater for algae growth, interest has grown in the possibility of adapting lipid rich, freshwater algae to a seawater environment. Seawater can have up to 35 grams of NaCl salt per liter more than freshwater. The Scenedesmus Dimorphus algae was chosen as the interest of this research due to its high lipid content. Also, it is very robust and well researched. Algae is grown in a controlled environment with varying salinity levels in either a bioreactor unit or 2-liter glass bottles. The objective of this research is to gradually adapt the S. dimorphus to increasing salt levels and reach a total specific gravity level of 1.010, which is about 16 grams NaCl per liter, compared to 1.025 TSG level that of seawater.https://engagedscholarship.csuohio.edu/u_poster_2017/1043/thumbnail.jp

Remnant for all Black Objects due to Gravity's Rainbow

We argue that a remnant is formed for all black objects in gravity's rainbow. This will be based on the observation that a remnant depends critically on the structure of the rainbow functions, and this dependence is a model independent phenomena. We thus propose general relations for the modified temperature and entropy of all black objects in gravity's rainbow. We explicitly check this to be the case for Kerr, Kerr-Newman-dS, charged-AdS, and higher dimensional Kerr-AdS black holes. We also try to argue that a remnant should form for black Saturn in gravity's rainbow. This work extends our previous results on remnants of Schwarzschild black holes [ arXiv:1402.5320] and black rings [arXiv:1409.5745].Comment: 21 pages, 13 figures, Accepted in Nucl.Phys.

Sensorless torque/force control

Motion control systems represent a main subsystem for majority of processing systems that can be found in the industrial sector. These systems are concerned with the actuation of all devices in the manufacturing process such as machines, robots, conveyor systems and pick and place mechanisms such that they satisfy certain motion requirements, e.g., the pre specified reference trajectories are followed along with delivering the proper force or torque to the point of interest at which the process occurs. In general, the aim of force/torque control is to impose the desired force on the environment even if the environment has dynamical motion