Professor David L Wiltshire
Physics and Astronomy
Phone: +64 3 364 2987 ext. 95128
Office: Physics 714
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 higherdimensional unified models, including socalled brane worlds, in which I was a pioneer. I have made many contributions on higherdimensional 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 “quasilocal 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

Quasilocal gravitational energy

Variance in the Hubble expansion

Averaging in cosmology

Backreaction 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: 2016PhD/DMA/EdDHeinesen, Asta

PhD  Li Y: 2014PhD/DMA/EdDLi, Yongzhuang
Completed

PhD  Carter BMN: Higher dimensional gravity, black holes and brane worlds (2002)

PhD  Leith BM: Scalar fields and alternatives in black holes and cosmology (2003)

PhD  Nazer MA: Cosmic microwave background anisotropies in an inhomogeneous universe (2010)

PhD  Ng SC: Cosmological models with quintessence: Dynamical properties and observational constraints (1998)

PhD  Nielsen AB: Black hole horizons and black hole thermodynamics (2003)

PhD  Smale PR: Observations and inhomogeneity in cosmology (2008)

PhD  Uzun N: An investigation of quasilocal systems in general relativity (2012)

Masters  Dam L: Inhomogeneous cosmological models and the Cosmic Microwave Background (2015)

Masters  Duley JAG: Average cosmic evolution in a lumpy universe (2010)

Masters  McKay J: The cosmological rest frame (2014)

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  HackettJones EJ: Optical reference geometry in four and five dimensions (1999)

Honours  Kontoleon N: Operator ordering problem of the WheelerDeWitt 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 LindquistWheeler 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 Article

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 nonlinear hubble expansion variation. Monthly Notices of the Royal Astronomical Society 457(3): 32853305. 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/10.1088/02649381/32/21/215021.

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): L91L94. http://dx.doi.org/10.1086/527034.
Edited Volume

Wiltshire DL., Visser M. and Scott SM. (Ed.) (2009) The Kerr spacetime: rotating black holes in general relativity. Cambridge: Cambridge University Press.
Chapter

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: 203244. Cambridge: Cambridge Scientific Publishers.

Wiltshire DL. (2008) Dark energy without dark energy. In KlapdorKleingrothaus HV; Lewis GF (Ed.), Dark Matter in Astroparticle and Particle Physics: Proceedings of the 6th International Heidelberg Conference: 564596. Singapore: World Scientific.
Conference Contribution  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), 1824 Jan 2009. In DARK 2009: 397412. http://dx.doi.org/10.1142/9789814293792_0032.

Wiltshire DL. (2010) Gravitational energy as dark energy: Average observational quantities. In AIP Conference Proceedings 1241: 11821191. 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, 711 Jul 2008. In EAS Publications Series 36: 9198. http://dx.doi.org/10.1051/eas/0936011.