A. L. James
A5012977113- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Geophysics and Gravity Measurements
- High-pressure geophysics and materials
- Dark Matter and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Geophysics and Sensor Technology
- Astronomy and Astrophysical Research
- Magnetic confinement fusion research
- Radio Astronomy Observations and Technology
- Adaptive optics and wavefront sensing
- Particle physics theoretical and experimental studies
- Cold Atom Physics and Bose-Einstein Condensates
- Black Holes and Theoretical Physics
- Stellar, planetary, and galactic studies
- Superconducting Materials and Applications
- Astrophysics and Cosmic Phenomena
- Quantum Mechanics and Applications
- Solar Radiation and Photovoltaics
- Radiology practices and education
- Noncommutative and Quantum Gravity Theories
- Wireless Communication Networks Research
- Galaxies: Formation, Evolution, Phenomena
California Institute of Technology
2024-2025
Cardiff University
2020-2024
University College London
2012
University of Trieste
2011
Institute for Space Astrophysics and Planetology
2011
National Institute for Astrophysics
2011
SUNY Geneseo
2010
Theories of quantum gravity based on the holographic principle predict existence fluctuations distance measurements that accumulate and exhibit correlations over macroscopic distances. This paper models an expected signal due to this phenomenology, details design estimated sensitivity co-located twin table-top 3D interferometers being built measure or constrain it. The experiment is be sensitive displacements $\sim10^{-19}\,\rm{m}/\sqrt{\rm{Hz}}$ in a frequency band between 1 250 MHz,...
Precision measurements of space and time, like those made by the detectors Laser Interferometer Gravitational-wave Observatory (LIGO), are often confronted with fundamental limitations imposed quantum mechanics. The Heisenberg uncertainty principle dictates that position momentum an object cannot both be precisely measured, giving rise to apparent limitation called Standard Quantum Limit (SQL). Reducing noise below SQL in gravitational-wave detectors, where photons used continuously measure...
Euclid-VIS is a large format visible imager for the ESA Euclid space mission in their Cosmic Vision program, scheduled launch 2019. Together with near infrared imaging within NISP instrument it forms basis of weak lensing measurements Euclid. VIS will image single r+i+z band from 550-900 nm over field view ~0.5 deg2. By combining 4 exposures total 2240 sec, reach to V=24.5 (10{\sigma}) sources extent ~0.3 arcsec. The sampling 0.1 provide deep tightly controlled and stable point spread...
We present multiphase Period-Color/Amplitude-Color/Period-Luminosity relations using OGLE III and Galactic Cepheid data compare with state of the art theoretical pulsation models. Using this new way to models observations, we find convincing evidence that both Period-Color Period-Luminosity Relations as a function phase are dynamic highly nonlinear at certain phases. extend Wesenheit same result. Hence our results cannot be due reddening errors. statistical tests urls movies depicting...
The experimental investigation of fundamental theories Physics nowadays is more and related to the development new cutting-edge technologies. We are exploiting most advanced techniques used in gravitational waves detectors search for quantum fluctuations space-time as predicted by some gravity. For this purpose, we building twin co-located interferometers that targeted achieve unprecedented levels sensitivity. Exploiting technology, like squeezed states light, will allow further reduction...
The Quantum-Enhanced Space-Time (QUEST) experiment consists of a pair co-located Power Recycled Michelson Interferometers, each designed to have broadband, shot-noise limited displacement sensitivity $2\times10^{-19}$ $\mathrm{m/\sqrt{Hz}}$ from 1 200 MHz. Here we present the first results QUEST that set new upper limits on correlated length fluctuations 13 80 MHz, constituting broadband constraints for stochastic gravitational wave background at these frequencies. In coincident observing...
The Any Light Particle Search II (ALPS II) is an experiment currently being built at DESY in Hamburg, Germany, that will use a light-shining-through-a-wall (LSW) approach to search for axion-like particles. ALPS represents significant step forward these types of experiments as it 24 superconducting dipole magnets, along with dual, high-finesse, 122 m long optical cavities. This paper gives the first comprehensive recipe realization idea, proposed over 30 years ago, cavities before and after...
With the use of twin, co-located, 3D interferometers, Cardiff University's Gravity Exploration Institute aims to observe quantum fluctuations space-time as predicted by some theories gravity. Our design displacement sensitivity exceeds that previous similar experiments, which have constrained magnitudes in 1-25 MHz band. The increased comes large part from comparably higher circulating power we aim achieve, reduces overall shot noise. One complication is an increase contrast defect light,...