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Full-Text Articles in Physics
An Analysis Of The Gravitational Waves Null Memory, Maria Babiuc-Hamilton
An Analysis Of The Gravitational Waves Null Memory, Maria Babiuc-Hamilton
Physics Faculty Research
Gravitational wave astronomy sees (hears) gravitational waves by observing the phenomena of gravitational and electromagnetic memory, and the formation of trapped surfaces and horizons.
Characteristics Of Gravitational And Electromagnetic Radiation, Maria Babiuc-Hamilton
Characteristics Of Gravitational And Electromagnetic Radiation, Maria Babiuc-Hamilton
Physics Faculty Research
Gravitational waves from the early universe are detectable, but detection is difficult. The strain is extremely small of magnitude 10-3 the width of a proton. There are detection and computational challenges.
Dawn Of Gravitational Wave Astronomy, Maria Babiuc-Hamilton
Dawn Of Gravitational Wave Astronomy, Maria Babiuc-Hamilton
Physics Faculty Research
This presentation chronicles the discovery of gravity waves.
Gravity & Electromagnetism On The Null Cone, Maria Babiuc-Hamilton
Gravity & Electromagnetism On The Null Cone, Maria Babiuc-Hamilton
Physics Faculty Research
Gravitational and electromagnetic radiation travel along light rays, which are principal null directions in space-time. They are characteristic surfaces of Einstein and Maxwell equations. In characteristic coordinates, the field is described by ordinary differential equations.
Adding Light To The Gravitational Waves On The Null Cone, Maria Babiuc-Hamilton
Adding Light To The Gravitational Waves On The Null Cone, Maria Babiuc-Hamilton
Physics Faculty Research
Recent interesting astrophysical observations point towards a multi-messenger, multi-wavelength approach to understanding strong gravitational sources, like compact stars or black hole collisions, supernovae explosions, or even the big bang. Gravitational radiation is properly defined only at future null infinity, but usually is estimated at a finite radius, and then extrapolated. Our group developed a characteristic waveform extraction tool, implemented in an open source code, which computes the gravitational waves infinitely far from their source, in terms of compactified null cones, by numerically solving Einstein equation in Bondi space-time coordinates. The goal is extend the capabilities of the code, by solving …
Fracture And Failure Of Nanoparticle Monolayers And Multilayers, Yifan Wang, Pongsakorn Kanjanaboos, Edward Barry Edward Barry, Sean P. Mcbride, Xiao-Min Lin, Heinrich M. Jaeger
Fracture And Failure Of Nanoparticle Monolayers And Multilayers, Yifan Wang, Pongsakorn Kanjanaboos, Edward Barry Edward Barry, Sean P. Mcbride, Xiao-Min Lin, Heinrich M. Jaeger
Physics Faculty Research
We present an experimental investigation of fracture in self-assembled gold nanoparticle mono- and multilayers attached to elastomer substrates and subjected to tensile stress. Imaging the fracture patterns down to the scale of single particles provides detailed information about the crack width distribution and allows us to compare the scaling of the average crack spacing as a function of strain with predictions by shear-lag models. With increasing particle size, the fracture strength is found to increase while it decreases as the film thickness is built up layer by layer, indicating stress inhomogeneity in the thickness dimension.
Evidence Of Longitudinal Acoustic Phonon Generation In Si Doping Superlattices By Ge Prism-Coupled Thz Laser Radiation, Thomas E. Wilson, Konstantin Korolev, Erich Kasper, Michael Oehme, Jörg Schulze
Evidence Of Longitudinal Acoustic Phonon Generation In Si Doping Superlattices By Ge Prism-Coupled Thz Laser Radiation, Thomas E. Wilson, Konstantin Korolev, Erich Kasper, Michael Oehme, Jörg Schulze
Physics Faculty Research
We report on the direct excitation of 246 GHz longitudinal acoustic phonons in silicon doping superlattices by the resonant absorption of nanosecond-pulsed far-infrared laser radiation of the same frequency. A longitudinally polarized evanescent laser light field is coupled to the superlattice through a germanium prism providing total internal reflection at the superlattice interface. The ballistic phonon signal is detected by a superconducting aluminum bolometer. The sample is immersed in low-temperature liquid helium.