UC SPARK - University of Canterbury - New Zealand

Professor David L Wiltshire

Physics and Astronomy

Fields of Research

  • General relativity and gravitation
  • Cosmology
  • Black holes
  • Quantum gravity

Researcher Summary

My interests broadly cover general relativity, quantum gravity and cosmology. Early in my career my main contributions were on gravitational aspects of higher-dimensional unified models, including so-called brane worlds, in which I was a pioneer. I have made many contributions on higher-dimensional black holes, and have also worked in quantum cosmology. More recently, I have become interested in the challenges to theoretical cosmology posed by new observations, in particular by cosmic acceleration and “dark energy”. I have revisited old assumptions concerning the operational interpretation of measurements in cosmology, and the way we average a universe, which is in fact very lumpy, with galaxy clusters strung in filaments and sheets around huge voids. “Dark energy” may in fact be a misidentification of “quasi-local gravitational energy”, an aspect of Einstein’s theory that we have yet to fully understand. I have proposed a viable alternative to the standard model - the timescape cosmology. My team and I are testing its properties. In future we aim to more deeply understand the nature of gravitational energy by rigorously construct a modified statistical geometry for the universe. The aim is to understand "dark energy" and possibly also "dark matter" as a modified geometrical theory of gravity rather than new exotic "stuff".

Subject Area: Disciplines

Future Research

  • Quasi-local gravitational energy
  • Variance in the Hubble expansion
  • Averaging in cosmology
  • Back-reaction in cosmology
  • Cosmic microwave background analysis
  • Foundations of physics
  • Galaxy clustering statistics
  • Inhomogeneous cosmologies
  • Type Ia supernovae analysis
  • Primordial inflation

Affiliations

Student Supervision

Displaying all items.
    Current
  • PhD - Heinesen A: 2016-PhD/DMA/EdD-Heinesen, Asta
  • PhD - Li Y: 2014-PhD/DMA/EdD-Li, Yongzhuang
  • Completed
  • PhD - Carter BMN: Higher dimensional gravity, black holes and brane worlds (2006)
  • PhD - Leith BM: Scalar fields and alternatives in black holes and cosmology (2007)
  • PhD - Nazer MA: Cosmic microwave background anisotropies in an inhomogeneous universe (2014)
  • PhD - Ng SC: Cosmological models with quintessence: Dynamical properties and observational constraints (2001)
  • PhD - Nielsen AB: Black hole horizons and black hole thermodynamics (2007)
  • PhD - Smale PR: Observations and inhomogeneity in cosmology (2012)
  • PhD - Uzun N: An investigation of quasilocal systems in general relativity (2016)
  • Masters - Dam L: Inhomogeneous cosmological models and the Cosmic Microwave Background (2016)
  • Masters - Duley JAG: Average cosmic evolution in a lumpy universe (2011)
  • Masters - McKay J: The cosmological rest frame (2015)
  • Honours - Adshead PJ: Scalar fields as a candidate for dark matter (2004)
  • Honours - Bonifacio J: Brownian motion in curved spacetimes (2012)
  • Honours - Cohen MI: Quantum mechanical bound states on black hole backgrounds (2002)
  • Honours - Dam L: Shape dynamics and Birkhoff's theorem (2014)
  • Honours - Frost H: Hamiltonian gauge systems: With application to general relativity and shape dynamics (2014)
  • Honours - Frost WT: Apparent and average acceleration of the universe (2010)
  • Honours - Grivell IJ: Primordial nucleosynthesis (1994)
  • Honours - Hackett-Jones EJ: Optical reference geometry in four and five dimensions (1999)
  • Honours - Kontoleon N: Operator ordering problem of the Wheeler-DeWitt equation (1996)
  • Honours - Lee HY: Cosmological background and perturbations (2011)
  • Honours - McKay JH: Quasilocal energy and conservation laws in general relativity (2013)
  • Honours - Neill CL: General relativistic galaxy models (2011)
  • Honours - Nguyen Phan TT: Cosmology as geodesic motion (2005)
  • Honours - O'Donnell KC: Optical properties of the Lindquist-Wheeler cosmology (2011)
  • Honours - Prain AJ: The optical geometry (2004)
  • Honours - Smith ML: The exact uncertainty principle on a curved space (2003)
  • Honours - Stone SC: Quintessential inflation (2002)
  • Honours - Yao H: Averaging the inhomogeneous universe (2006)

Research/Scholarly/Creative Works

(Displaying research/scholarly/creative work for 2007 - present)
Journal Articles
  • Dam LH., Heinesen A. and Wiltshire DL. (2017) Apparent cosmic acceleration from type Ia supernovae. Monthly Notices of the Royal Astronomical Society 472(1): 835-851. http://dx.doi.org/10.1093/mnras/stx1858.
  • Buchert T., Coley AA., Kleinert H., Roukema BF. and Wiltshire DL. (2016) Observational challenges for the standard FLRW model. International Journal of Modern Physics D 25(3) ARTN 1630007: 17. http://dx.doi.org/10.1142/S021827181630007X.
  • McKay JH. and Wiltshire DL. (2016) Defining the frame of minimum non-linear Hubble expansion variation. Monthly Notices of the Royal Astronomical Society 457(3): 3285-3305. http://dx.doi.org/10.1093/mnras/stw128.
  • Buchert T., Carfora M., Ellis GFR., Kolb EW., MacCallum MAH., Ostrowski JJ., Rasanen S., Roukema BF., Andersson L. and Coley AA. (2015) Is there proof that backreaction of inhomogeneities is irrelevant in cosmology? Classical and Quantum Gravity 32(21) ARTN 215021: 38. http://dx.doi.org/10.1088/0264-9381/32/21/215021.
  • Nazer MA. and Wiltshire DL. (2015) Cosmic microwave background anisotropies in the timescape cosmology. Physical Review D: Particles, Fields, Gravitation, and Cosmology 91(6) 63519: 28pp. http://dx.doi.org/10.1103/PhysRevD.91.063519.
  • Wiltshire DL., Smale PR., Mattsson T. and Watkins R. (2013) Hubble flow variance and the cosmic rest frame. Physical Review D: Particles, Fields, Gravitation, and Cosmology 88(8) 83529: 37pp. http://dx.doi.org/10.1103/PhysRevD.88.083529.
  • Leith BM., Ng SCC. and Wiltshire DL. (2008) Gravitational energy as dark energy: Concordance of cosmological tests. ASTROPHYSICAL JOURNAL LETTERS 672(2): L91-L94. http://dx.doi.org/10.1086/527034.
Edited Volumes
  • Wiltshire DL., Visser M. and Scott SM. (Ed.) (2009) The Kerr spacetime: rotating black holes in general relativity. Cambridge: Cambridge University Press.
Chapters
  • Wiltshire DL. (2014) Cosmic structure, averaging and dark energy. In Perez Bergliaffa SE; Novello M (Ed.), Proceedings of XVth Brazilian School of Cosmology and Gravitation: 203-244. Cambridge: Cambridge Scientific Publishers.
  • Wiltshire DL. (2008) Dark energy without dark energy. In Klapdor-Kleingrothaus HV; Lewis GF (Ed.), Dark Matter in Astroparticle and Particle Physics: Proceedings of the 6th International Heidelberg Conference: 564-596. Singapore: World Scientific.
Conference Contributions - Published
  • Wiltshire DL. (2010) Dark energy without dark energy: Average observational quantities. Christchurch, New Zealand: 7th International Heidelberg Conference on Dark Matter in Astrophysics and Particle Physics (DARK 2009), 18-24 Jan 2009. In DARK 2009: 397-412. http://dx.doi.org/10.1142/9789814293792_0032.
  • Wiltshire DL. (2010) Gravitational energy as dark energy: Average observational quantities. Paris, France: Invisible Universe, 29 Jun-3 Jul 2009. In AIP Conference Proceedings 1241: 1182-1191. http://dx.doi.org/10.1063/1.3462616.
  • Wiltshire DL. (2009) Gravitational energy as dark energy: Towards concordance cosmology without Lambda. Lyon, France: Dark Energy and Dark Matter: Observations, Experiments and Theories, 7-11 Jul 2008. In EAS Publications Series 36: 91-98. http://dx.doi.org/10.1051/eas/0936011.