Skip to main content
Home
Department Of Physics text logo
  • Research
    • Our research
    • Our research groups
    • Our research in action
    • Research funding support
    • Summer internships for undergraduates
  • Study
    • Undergraduates
    • Postgraduates
  • Engage
    • For alumni
    • For business
    • For schools
    • For the public
Menu
Space and Planets (artistic image)
Credit: hdwallpaperim.com/

Gianluca Gregori

Professor of Physics

Research theme

  • Lasers and high energy density science
  • Plasma physics

Sub department

  • Atomic and Laser Physics

Research groups

  • Laboratory astroparticle physics
  • Oxford Centre for High Energy Density Science (OxCHEDS)
Gianluca.Gregori@physics.ox.ac.uk
Telephone: 01865 (2)82639
Clarendon Laboratory, room 029.8
  • About
  • Publications

Theory of x-ray photon correlation spectroscopy for multiscale flows

Physical Review Research American Physical Society (APS) (2025)
More details from the publisher

Modeling of warm dense hydrogen via explicit real-time electron dynamics: Electron transport properties

Physical Review E American Physical Society (APS) 111:4 (2025) 045208

Authors:

Pontus Svensson, Patrick Hollebon, Daniel Plummer, Sam M Vinko, Gianluca Gregori
More details from the publisher

Bounds on Heavy Axions with an X-Ray Free Electron Laser

Physical Review Letters American Physical Society (APS) 134:5 (2025) 55001

Authors:

Jack WD Halliday, Giacomo Marocco, Konstantin A Beyer, Charles Heaton, Motoaki Nakatsutsumi, Thomas R Preston, Charles D Arrowsmith, Carsten Baehtz, Sebastian Goede, Oliver Humphries, Alejandro Laso Garcia, Richard Plackett, Pontus Svensson, Georgios Vacalis, Justin Wark, Daniel Wood, Ulf Zastrau, Robert Bingham, Ian Shipsey, Subir Sarkar, Gianluca Gregori

Abstract:

<jats:p>We present new exclusion bounds obtained at the European X-Ray Free Electron Laser facility (EuXFEL) on axionlike particles in the mass range <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msup><a:mrow><a:mn>10</a:mn></a:mrow><a:mrow><a:mo>−</a:mo><a:mn>3</a:mn></a:mrow></a:msup><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mrow><a:mi>eV</a:mi></a:mrow><a:mo>≲</a:mo><a:msub><a:mrow><a:mi>m</a:mi></a:mrow><a:mrow><a:mi>a</a:mi></a:mrow></a:msub><a:mo>≲</a:mo><a:msup><a:mrow><a:mn>10</a:mn></a:mrow><a:mrow><a:mn>4</a:mn></a:mrow></a:msup><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mi>eV</a:mi></a:mrow></a:math>. Our experiment exploits the Primakoff effect via which photons can, in the presence of a strong external electric field, decay into axions, which then convert back into photons after passing through an opaque wall. While similar searches have been performed previously at a third-generation synchrotron [Yamaji , ], our work demonstrates improved sensitivity, exploiting the higher brightness of x-rays at EuXFEL.</jats:p> <jats:sec> <jats:title/> <jats:supplementary-material> <jats:permissions> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material> </jats:sec>
More details from the publisher
More details
More details

Ionic structure, liquid-liquid phase transitions, x-ray diffraction, and x-ray Thomson scattering in shock-compressed liquid silicon in the 100-200 GPa regime

Physical Review E American Physical Society 111:1 (2025) 015205

Authors:

MW Chandre Dharma-wardana, Dennis D Klug, Hannah Poole, Gianluca Gregori

Abstract:

Recent cutting-edge experiments have provided in situ structure characterization and measurements of the pressure (P), density (¯ρ) and temperature (T) of shock compressed silicon in the 100 GPa range of pressures and up to ∼10,000K. We present first-principles calculations in this P, T, ρ¯ regime to reveal a plethora of novel liquid-liquid phase transitions (LPTs) identifiable via discontinuities in the pressure and the compressibility. Evidence for the presence of a highly-correlated liquid (CL) phase, as well as a normal-liquid (NL) phase at the LPTs is presented by a detailed study of one LPT. The LPTs make the interpretation of these experiments more challenging. The LPTs preserve the short-ranged ionic structure of the fluid by collective adjustments of many distant atoms when subject to compression and heating, with minimal change in the ion-ion pair-distribution functions, and in transport properties such as the electrical and thermal conductivities σ and κ. We match the experimental X-Ray Thomson scattering and X-ray diffraction data theoretically, and provide pressure isotherms, ionization data and compressibilities that support the above picture of liquid silicon as a highly complex LPT-driven “glassy” metallic liquid. These novel results are relevant to materials research, studies of planetary interiors, high-energy-density physics, and in laser-fusion studies.
More details from the publisher
Details from ORA
More details

Efficient micromirror confinement of sub-teraelectronvolt cosmic rays in galaxy clusters

Nature Astronomy Nature Research 9:3 (2025) 438-448

Authors:

Patrick Reichherzer, Archie Bott, Robert Ewart, Gianluca Gregori, Kempski Philipp, Kunze Matthew, Alexander Schekochihin

Abstract:

Cosmic rays (CRs) play a pivotal role in shaping the thermal and dynamical properties of astrophysical environments, such as galaxies and galaxy clusters. Recent observations suggest a stronger confinement of CRs in certain astrophysical systems than predicted by current CR-transport theories. Here, we show that the incorporation of microscale physics into CR-transport models can account for this enhanced CR confinement. We develop a theoretical description of the effect of magnetic microscale fluctuations originating from the mirror instability on macroscopic CR diffusion. We confirm our theory with large-dynamical-range simulations of CR transport in the intracluster medium (ICM) of galaxy clusters and kinetic simulations of CR transport in micromirror fields. We conclude that sub-teraelectronvolt CR confinement in the ICM is far more effective than previously anticipated on the basis of Galactic-transport extrapolations. The transformative impact of micromirrors on CR diffusion provides insights into how microphysics can reciprocally affect macroscopic dynamics and observable structures across a range of astrophysical scales.
More details from the publisher
Details from ORA
More details

Pagination

  • Current page 1
  • Page 2
  • Page 3
  • Page 4
  • Page 5
  • Page 6
  • Page 7
  • Page 8
  • Page 9
  • …
  • Next page Next
  • Last page Last

Footer Menu

  • Contact us
  • Giving to the Dept of Physics
  • Work with us
  • Media

User account menu

  • Log in

Follow us

FIND US

Clarendon Laboratory,

Parks Road,

Oxford,

OX1 3PU

CONTACT US

Tel: +44(0)1865272200

University of Oxfrod logo Department Of Physics text logo
IOP Juno Champion logo Athena Swan Silver Award logo

© University of Oxford - Department of Physics

Cookies | Privacy policy | Accessibility statement

Built by: Versantus

  • Home
  • Research
  • Study
  • Engage
  • Our people
  • News & Comment
  • Events
  • Our facilities & services
  • About us
  • Current students
  • Staff intranet