Physical Sciences and Mathematics Commons^™

Tests Of Lorentz Symmetry In The Gravitational Sector, Aurélien Hees, Quentin G. Bailey, Adrien Bourgoin, Hélène Pihan-Le Bars, Christine Guerlin, Christophe Le Poncin-Lafitte

Quentin Bailey

Lorentz symmetry is one of the pillars of both General Relativity and the Standard Model of particle physics. Motivated by ideas about quantum gravity, unification theories and violations of CPT symmetry, a significant effort has been put the last decades into testing Lorentz symmetry. This review focuses on Lorentz symmetry tests performed in the gravitational sector. We briefly review the basics of the pure gravitational sector of the Standard-Model Extension (SME) framework, a formalism developed in order to systematically parametrize hypothetical violations of the Lorentz invariance. Furthermore, we discuss the latest constraints obtained within this formalism including analyses of the …

Prospects For Sme Tests With Experiments At Syrte And Lkb, C. Guerlin, H. Pihan-Le Bars, Q. G. Bailey, P. Wolf

Quentin Bailey

Preliminary work has been done in order to assess the perspectives of metrology and fundamental physics atomic experiments at SYRTE and LKB in the search for physics beyond the Standard Model and General Relativity. The first studies we identified are currently ongoing with the Microscope mission and with a Cs fountain clock. The latter brings significant improvement on the proton-sector coefficient cTT down to the 10−17 GeV level.

Improved Tests Of Lorentz Invariance In The Matter Sector Using Atomic Clocks, H. Pihan-Le Bars, C. Guerlin, Q. G. Bailey, S. Bize, P. Wolf

Quentin Bailey

For the purpose of searching for Lorentz-invariance violation in the minimal Standard-Model Extension, we perfom a reanalysis of data obtained from the 133Cs fountain clock operating at SYRTE. The previous study led to new limits on eight components of the ˜cµν tensor, which quantifies the anisotropy of the proton’s kinetic energy. We recently derived an advanced model for the frequency shift of hyperfine Zeeman transition due to Lorentz violation and became able to constrain the ninth component, the isotropic coefficient c˜TT, which is the least well-constrained coefficient of ˜cµν. This model is based on a second-order boost Lorentz transformation from …

Lorentz-Violating Electromagnetostatics, Quentin G. Bailey

Quentin Bailey

In this talk, the stationary limit of Lorentz-violating electrodynamics is discussed. As illustrated by some simple examples, the general solution includes unconventional mixing of electrostatic and magnetostatic effects. I discuss a high-sensitivity null-type measurement, exploiting Lorentz-violating electromagnetostatic effects, that could improve existing limits on parity-odd coefficients for Lorentz violation in the photon sector.

Gravity Sector Of The Sme, Q. G. Bailey

Quentin Bailey

In this talk, the gravity sector of the effective field theory description of local Lorentz violation is discussed, including minimal and nonminimal curvature couplings. Also, recent experimental and observational analyses including solar-system ephemeris and short-range gravity tests are reviewed.

Dynamical Spacetime Symmetry, Benjamin Lovelady, James Thomas Wheeler

Benjamin Lovelady

According to the Coleman-Mandula theorem, any gauge theory of gravity combined with an internal symmetry based on a Lie group must take the form of a direct product in order to be consistent with basic assumptions of quantum field theory. However, we show that an alternative gauging of a simple group can lead dynamically to a spacetime with compact internal symmetry. The biconformal gauging of the conformal symmetry of n-dimensional Euclidean space doubles the dimension to give a symplectic manifold. Examining one of the Lagrangian submanifolds in the flat case, we find that in addition to the expected SO(n) connection …

Removal Versus Ablation In Krf Dry Laser Cleaning Of Polystyrene Particles From Silicon, Sergey I. Kudryashov, Susan D. Allen

Susan D. Allen

Direct absorption and melting of 0.2, 0.5 and 1.1 μm polystyrene particles on a Si substrate irradiated by 248 nm excimer laser radiation was found to contribute to their dry laser removal via a "hopping" mechanism at cleaning thresholds of 0.05, 0.1, and 0.16 J/cm ², respectively. Ablation of these particles, which starts near the beginning of substrate deceleration at fluences above 0.4-0.5 J/cm ², suppresses particle removal due to ablative recoil momentum. At fluences above a second cleaning threshold of 0.7 J/cm ² particles are completely evaporated without any visible surface damage of the Si substrate.

© …

Photoacoustic Study Of Krf Laser Heating Of Si: Implications For Laser Particle Removal, Sergey I. Kudryashov, Susan D. Allen

Susan D. Allen

A photoacoustic study of KrF laser heating of Si has revealed that the dominant mechanism of acoustic generation is thermoacoustic with a considerable contribution from the concentration-deformation mechanism at laser fluences below the Si melting threshold of 0.5 J/cm ². Upon Si melting the contraction of the molten material contributes significantly to acoustic generation. At fluences above 1.4 J/cm ² laser ablation of the molten layer enhances the amplitude of the compression pulse and diminishes that of the rarefaction pulse. The results of photoacoustic measurements allow optimization of experimental conditions for dry laser particle removal.

© 2002 American Institute …

Optical Transmission Measurements Of Explosive Boiling And Liftoff Of A Layer Of Micron-Scale Water Droplets From A Krf Laser-Heated Si Substrate, Sergey I. Kudryashov, Susan D. Allen

Susan D. Allen

Water plume velocities were measured in air by optical transmission as a function of laser fluence using a KrF laser for explosive boiling and liftoff of a layer of micron-scale waterdroplets from a laser-heated Si substrate of interest for laser particle removal. The thickness of the superheated water layer near the water/Si interface determines acceleration and removal of the waterdroplets from the Si substrate.

© 2003 American Institute of Physics

Analysis Of Adsorbed Contaminants Of Caf2 Surfaces By Infrared Laser Induced Desorption, Jinmei Fu, Yamini Surapaneni, Susan D. Allen

Susan D. Allen

157 nm photolithography technologies are currently under development and have been accepted as the leading candidate for fabrication of the next generation semiconductor devices after 193 nm. At this and shorter wavelengths, molecular contamination of surfaces becomes a serious problem as almost all molecules absorb at 157 nm and below. The light transmitted by a photolithographic tool can be significantly decreased by the presence of a few monolayers adsorbed on its many optical surfaces. We have developed a laser induced desorption, electron impact ionization, time-of-flight mass spectrometer (LID TOFMS) to study contaminants on 157nm and other ultraviolet optics, e.g., polished …

Parametric Generation Of Multimegahertz Acoustic Oscillations In Laser-Generated Multibubble System In Bulk Water, Sergey I. Kudryashov, Kevin Lyon, Susan D. Allen

Susan D. Allen

Using a nanosecond C O2 laser for explosive surface boiling of bulk water, oscillatory acoustic transients from steam bubbles were recorded using a contact photoacoustic technique. Multiple well-resolved, high-amplitude multimegahertz spectral features reflecting parametric interactions between oscillations of cavitating steam bubbles were revealed in the fast Fourier transformation spectra of these transients. A potential parametric generation mechanism for these oscillation modes of steam bubbles is discussed.

© 2006 American Institute of Physics.

Thermodynamics Of The Solar Corona And Evolution Of The Solar Magnetic Field As Inferred From The Total Solar Eclipse Observations Of 2010 July 11, Shadia Rifai Habbal, Miloslav Druckmüller, Huw Morgan, Adalbert Ding, Judd Johnson, Hana Druckmüllerová, Adrian Daw, Martina B. Arndt, Martin Dietzel, Jon Saken

Jon Saken

We report on the first multi-wavelength coronal observations, taken simultaneously in white light, Hα 656.3 nm, Fe IX 435.9 nm, Fe X 637.4 nm, Fe XI 789.2 nm, Fe XIII 1074.7 nm, Fe XIV 530.3 nm, and Ni XV 670.2 nm, during the total solar eclipse of 2010 July 11 from the atoll of Tatakoto in French Polynesia. The data enabled temperature differentiations as low as 0.2 × 10⁶ K. The first-ever images of the corona in Fe IX and Ni XV showed that there was very little plasma below 5 × 10⁵ K and above 2.5 × …

Interpreting Particle Motion In Low-Gravity, Asteroidal Conditions With Image Processing And Analysis, Gillian Gomer, Adrienne Dove, Michael Fraser, Seamus Anderson, Kristen John, Marc Fries

Gillian Gomer

The Motion Of Two Identical Masses Connected By An Ideal String Symmetrically Placed Over A Corner, Asim Gangopadhyaya, Constantin Rasinariu

Constantin Rasinariu

We introduce a novel, two-mass system that slides up an inclined plane while its center of mass moves down. The system consists of two identical masses connected by an ideal string symmetrically placed over a corner-shaped support. This system is similar to a double-cone that rolls up an inclined set of V-shaped rails. We find the double-cone's motion easy to demonstrate but difficult to analyze. Our example here is more straightforward to follow, and the experimental observations are in good agreement with the theoretical predictions.

Building Confidence In The Dirac Δ-Function, Asim Gangopadhyaya, Constantin Rasinariu

Constantin Rasinariu

In this note we present an example from undergraduate quantum mechanics designed to highlight the versatility of the Dirac δ-function. Namely, we compute the expectation value of the Hamiltonian of a free particle in a state described by a triangular wave function ψ(x). Since the first derivative of ψ(x) is piecewise constant, and because this Hamiltonian is proportional to the second order spatial derivative, students often end up finding the expectation value to be zero—an unphysical answer. This problem provides a pedagogical application of the Dirac δ-function. By arriving at the same result via alternate pathways, this exercise reinforces students’ …

Generation Of Broadband Thz Pulses By Laser Wakefield At Radial Boundary Of Plasma Column, Serge Y. Kalmykov, Alexander Englesbe, Jennifer Elle, Andreas Schmitt-Sody

Serge Youri Kalmykov

A Numerical Investigation On Tidal And Gravity Wave Contributions To The Summer Time Na Variations In The Midlatitude E Region, Xuguang Cai, Titus Yuan, J. Vincent Eccles

Xuguang Cai

The Na density variations in the E region have been studied over the past few decades. Although considerable progress in understanding and in modeling the metal layer observations has been made, Na density features above 100 km have yet to be explained. Various studies have linked them to the Na⁺variations, a major reservoir for Na in E region. But the lack of comprehensive modeling investigations and of wind and temperature observations prevents further understanding on this important ion‐neutral coupling topic. In this study, we conduct a numerical simulation on the summer time Na density behavior in the midlatitude …

Large-Scale Gravity Wave Perturbations In The Mesopause Region Above Northern Hemisphere Midlatitudes During Autumnal Equinox: A Joint Study By The Usu Na Lidar And Whole Atmosphere Community Climate Model, Xuguang Cai, Titus Yuan, Han-Li Liu

Xuguang Cai

To investigate gravity wave (GW) perturbations in the midlatitude mesopause region during boreal equinox, 433h of continuous Na lidar full diurnal cycle temperature measurements in September between 2011 and 2015 are utilized to derive the monthly profiles of GW-induced temperature variance, T′^₂, and the potential energy density (PED). Operating at Utah State University (42°N, 112°W), these lidar measurements reveal severe GW dissipation near 90km, where both parameters drop to their minima (∼ 20K² and ∼50m²s⁻², respectively). The study also shows that GWs with periods of 3–5h dominate the midlatitude mesopause region during …

Call For Abstracts - Resrb 2019, July 8-9, Wrocław, Poland, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Historical Notes: Modern Dynamics

David D Nolte

A Companion To The Introduction To Modern Dynamics, David D. Nolte

David D Nolte