Dr Timothy Clifton

Research

Research Interests:

My research interests are in relativity, gravitation, and cosmology. I am particularly interested in the large-scale behaviour of inhomogeneous spacetimes, the emergence of homogeneity and isotropy in the context of the averaging and backreaction problems, the construction of tests for determining the geometry of the Universe, and the understanding and constraining of alternative theories of gravity. As well as being of foundational importance to cosmology, the study of these areas is strongly motivated by the apparent need for the universe to be more than two thirds filled with dark energy.

Publications

Recent publication and preprints can be found here.

• Clifton T, Gallagher CS, Goldberg S et al. (2020). Viable Gauge Choices in Cosmologies with Non-Linear Structures. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.101.063530

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/63539
• Gallagher CS, Clifton T, Clarkson C (2020). Multi-scale perturbation theory. Part I. Methodology and leading-order bispectrum corrections in the matter-dominated era. nameOfConference

  
  

  DOI: 10.1088/1475-7516/2020/03/011

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/64112
• Clifton T, Sussman RA (2019). Cosmological Backreaction in Spherical and Plane Symmetric Dust-Filled Space-Times. nameOfConference

  
  

  DOI: 10.1088/1361-6382/ab3a14

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/59843
• Durk J, Clifton T (2019). Discrete Cosmological Models in the Brans-Dicke Theory of Gravity. nameOfConference

  
  

  DOI: 10.1088/1361-6382/ab329e

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/59477
• Clifton T, Sanghai VAA (2019). Parametrizing theories of gravity on large and small scales in cosmology. nameOfConference

  
  

  DOI: 10.1103/PhysRevLett.122.011301

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/54505
• Gallagher CS, Clifton T (2018). Relativistic Euler equations in cosmologies with nonlinear structures. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.98.103516

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/54815
• CLIFTON TA, Bentivegna E, DURK J et al. (2018). Black-Hole Lattices as Cosmological Models. nameOfConference

  
  

  DOI: 10.1088/1361-6382/aac846

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/42983
• Goldberg SR, Gallagher C, Clifton T (2017). Perturbation theory for cosmologies with non-linear structure. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.96.103508

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/28975
• Durk J, Clifton T (2017). A quasi-static approach to structure formation in black hole universes. nameOfConference

  
  

  DOI: 10.1088/1475-7516/2017/10/012

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/28977
• Sanghai VAA, Fleury P, Clifton T (2017). Ray tracing and Hubble diagrams in post-Newtonian cosmology. nameOfConference

  
  

  DOI: 10.1088/1475-7516/2017/07/028

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/28364
• Clifton T, Carr B, Coley A (2017). Persistent black holes in bouncing cosmologies. nameOfConference

  
  

  DOI: 10.1088/1361-6382/aa6dbb

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/32421
• Bibi R, Clifton T, Durk J (2017). Cosmological solutions with charged black holes. nameOfConference

  
  

  DOI: 10.1007/s10714-017-2261-4

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/32422
• CLIFTON TA, Durk J (2017). Exact initial data for black hole universes with a cosmological constant. nameOfConference

  
  

  DOI: 10.1088/1361-6382/aa6064

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/21339
• Clifton T, Barrow JD (2017). Decay of the Cosmic Vacuum Energy. nameOfConference

  
  

  DOI: doi

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/54506
• CLIFTON TA, Sanghai V (2017). Parameterized post-Newtonian cosmology. nameOfConference

  
  

  DOI: 10.1088/1361-6382/aa5d75

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/19554
• Goldberg S, Clifton TA, Malik K (2017). Cosmology on all scales: A two-parameter perturbation expansion. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.95.043503

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/19364
• Clifton T, Gregoris D, Rosquist K (2017). The Magnetic Part of the Weyl Tensor, and the Expansion of Discrete Universes. nameOfConference

  
  

  DOI: 10.1007/s10714-017-2192-0

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/19131
• Clifton T, Gregoris D, Rosquist K (2017). The magnetic part of the Weyl tensor, and the expansion of discrete universes. nameOfConference

  
  

  DOI: 10.1007/s10714-017-2192-0

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/54508
• Sanghai VAA, Clifton T (2016). Cosmological backreaction in the presence of radiation and a cosmological constant. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.94.023505

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/14731
• Sanghai VAA, Clifton T (2016). Erratum: Post-Newtonian cosmological modelling (Physical Review D - Particles, Fields, Gravitation and Cosmology (2015) 91 (103532)). nameOfConference

  
  

  DOI: 10.1103/PhysRevD.93.089903

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/32423
• Sanghai VAA, Clifton T (2015). Post-Newtonian cosmological modelling. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.91.103532

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/18068
• Clifton T, Dunsby PKS (2015). On the emergence of accelerating cosmic expansion in f (R) theories of gravity. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.91.103528

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17810
• Clifton T, Gregoris D, Rosquist K (2015). Applications of black hole lattices in relativistic cosmology. nameOfConference

  
  

  DOI: 10.1063/1.4937219

  
  

  QMRO: qmroHref
• Clifton T (2014). The method of images in cosmology. nameOfConference

  
  

  DOI: 10.1088/0264-9381/31/17/175010

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17811
• Clifton T, Gregoris D, Rosquist K (2014). Piecewise silence in discrete cosmological models. nameOfConference

  
  

  DOI: 10.1088/0264-9381/31/10/105012

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17812
• Clifton T, Gregoris D, Rosquist K et al. (2013). Exact Evolution of Discrete Relativistic Cosmological Models. nameOfConference

  
  

  DOI: 10.1088/1475-7516/2013/11/010

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17818
• Clifton T, Ellis GFR, Tavakol R (2013). A Gravitational Entropy Proposal. nameOfConference

  
  

  DOI: 10.1088/0264-9381/30/12/125009

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17820
• CLIFTON TA (2013). BACK-REACTION IN RELATIVISTIC COSMOLOGY. nameOfConference

  
  

  DOI: 10.1142/S0218271813300048

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17821
• CLIFTON TA (2013). G. F. R. Ellis, R. Maartens and M. A. H. MacCallum: Relativistic cosmology. nameOfConference

  
  

  DOI: 10.1007/s10714-013-1543-8

  
  

  QMRO: qmroHref
• Clifton T, Dunsby P, Goswami R et al. (2012). On the absence of the usual weak-field limit, and the impossibility of embedding some known solutions for isolated masses in cosmologies with f(R) dark energy. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.87.063517

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/3762
• Clifton T, Coley A, van den Hoogen R (2012). Observational cosmology in macroscopic gravity. nameOfConference

  
  

  DOI: 10.1088/1475-7516/2012/10/044

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/3761
• Clifton T, Rosquist K, Tavakol R (2012). An exact quantification of backreaction in relativistic cosmology. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.86.043506

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17819
• Clifton T, Clarkson C, Bull P (2012). Isotropic Blackbody Cosmic Microwave Background Radiation as Evidence for a Homogeneous Universe. nameOfConference

  
  

  DOI: 10.1103/PhysRevLett.109.051303

  
  

  QMRO: qmroHref
• Clifton T, Clarkson C, Bull P (2012). The isotropic blackbody CMB as evidence for a homogeneous universe. nameOfConference

  
  

  DOI: 10.1103/PhysRevLett.109.051303

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17842
• CLIFTON TA, Bull P (2012). Local and non-local measures of acceleration in cosmology. nameOfConference

  
  

  DOI: doi

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/18954
• Bull P, Clifton T (2012). Local and nonlocal measures of acceleration in cosmology. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.85.103512

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/57035
• Clifton T, Ferreira PG, Padilla A et al. (2012). Modified gravity and cosmology. nameOfConference

  
  

  DOI: 10.1016/j.physrep.2012.01.001

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17822
• Clarkson C, Clifton T, Coley A et al. (2012). Observational constraints on the averaged universe. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.85.043506

  
  

  QMRO: qmroHref
• Clifton T, Ferreira PG, O'Donnell K (2012). Improved treatment of optics in the Lindquist-Wheeler models. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.85.023502

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17823
• CLIFTON TA, BULL, P, FERREIRA PG (2012). The kSZ effect as a test of general radial inhomogeneity in LTB cosmology. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.85.024002

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/57041
• Clifton T (2011). Cosmology without averaging. nameOfConference

  
  

  DOI: 10.1088/0264-9381/28/16/164011

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17847
• Shafieloo A, Clifton T, Ferreira P (2011). The crossing statistic: dealing with unknown errors in the dispersion of Type Ia supernovae. nameOfConference

  
  

  DOI: 10.1088/1475-7516/2011/08/017

  
  

  QMRO: qmroHref
• Clifton T (2011). Is Dark Energy an illusion?. nameOfConference

  
  

  DOI: 10.1016/j.ppnp.2011.01.004

  
  

  QMRO: qmroHref
• Clifton T, Banados M, Skordis C (2010). The parameterized post-Newtonian limit of bimetric theories of gravity. nameOfConference

  
  

  DOI: 10.1088/0264-9381/27/23/235020

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17850
• Clifton T, Zlosnik TG (2010). FRW cosmology in Milgrom's bimetric theory of gravity. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.81.103525

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17848
• Clifton T, Barrow JD (2010). Observational constraints on the completeness of space near astrophysical objects. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.81.063006

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17851
• Clifton T, Zuntz J (2009). Hubble diagram dispersion from large-scale structure. nameOfConference

  
  

  DOI: 10.1111/j.1365-2966.2009.15616.x

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17863
• Clifton T, Ferreira PG (2009). Errors in estimating Omega(Lambda) due to the fluid approximation. nameOfConference

  
  

  DOI: 10.1088/1475-7516/2009/10/026

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17849
• Clifton T, Ferreira PG (2009). Archipelagian Cosmology: Dynamics and Observables in a Universe with Discretized Matter Content. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.80.103503

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17843
• Clifton T, Ferreira PG, Zuntz J (2009). What the small angle CMB really tells us about the curvature of the Universe. nameOfConference

  
  

  DOI: 10.1088/1475-7516/2009/07/029

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17844
• Clarkson C, Clifton T, February S (2009). Perturbation theory in Lemaitre-Tolman-Bondi cosmology. nameOfConference

  
  

  DOI: 10.1088/1475-7516/2009/06/025

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17865
• Clifton T, Ferreira PG (2009). Does dark energy really exist?. nameOfConference

  
  

  DOI: 10.1038/scientificamerican0409-48

  
  

  QMRO: qmroHref
• Clifton T (2008). Higher powers in gravitation. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.78.083501

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17873
• Clifton T (2008). Properties of black hole radiation from tunnelling. nameOfConference

  
  

  DOI: 10.1088/0264-9381/25/17/175022

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17870
• Clifton T, Ferreira PG, Land K (2008). Living in a Void: Testing the Copernican Principle with Distant Supernovae. nameOfConference

  
  

  DOI: 10.1103/PhysRevLett.101.131302

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17866
• Clifton T, Weisberg JM (2008). A Simple Model for Pulse Profiles from Precessing Pulsars, with Special Application to Relativistic Binary PSR B1913+16. nameOfConference

  
  

  DOI: 10.1086/587049

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17868
• Clifton T (2008). Parametrized post-Newtonian limit of fourth-order theories of gravity. nameOfConference

  
  

  DOI: 10.1103/PhysRevD.77.024041

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17872
• Clifton T (2007). Exact Friedmann solutions in higher-order gravity theories. nameOfConference

  
  

  DOI: 10.1088/0264-9381/24/20/010

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17878
• Clifton T, Shenker S, Sivanandam N (publicationYear). Volume weighted measures of eternal inflation in the Bousso-Polchinski landscape. nameOfConference

  
  

  DOI: 10.1088/1126-6708/2007/09/034

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/18032
• Clifton T, Barrow JD (publicationYear). Ups and downs of cyclic universes. nameOfConference

  
  

  DOI: 10.1103/physrevd.75.043515

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17879
• Clifton T, Linde A, Sivanandam N (publicationYear). Islands in the landscape. nameOfConference

  
  

  DOI: 10.1088/1126-6708/2007/02/024

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17891
• Clifton T (2006). Spherically symmetric solutions to fourth-order theories of gravity. nameOfConference

  
  

  DOI: 10.1088/0264-9381/23/24/015

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/17890
• Barrow JD, Clifton T (publicationYear). Cosmologies with energy exchange. nameOfConference

  
  

  DOI: 10.1103/physrevd.73.103520

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/18030
• Clifton T, Barrow JD (publicationYear). Decaying gravity. nameOfConference

  
  

  DOI: 10.1103/physrevd.73.104022

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/18042
• Clifton T, Barrow JD (2006). Further exact cosmological solutions to higher-order gravity theories. nameOfConference

  
  

  DOI: 10.1088/0264-9381/23/9/011

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/18044
• Clifton T, Barrow JD (publicationYear). The existence of Gödel, Einstein, and de Sitter universes. nameOfConference

  
  

  DOI: 10.1103/physrevd.72.123003

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/18065
• Barrow JD, Clifton T (2006). Exact cosmological solutions of scale-invariant gravity theories. nameOfConference

  
  

  DOI: 10.1088/0264-9381/23/1/l01

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/18067
• Clifton T, Barrow JD (publicationYear). The power of general relativity. nameOfConference

  
  

  DOI: 10.1103/physrevd.72.103005

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/18045
• Clifton T, Barrow JD, Scherrer RJ (publicationYear). Constraints on the variation ofGfrom primordial nucleosynthesis. nameOfConference

  
  

  DOI: 10.1103/physrevd.71.123526

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/18066
• Clifton T, Mota DF, Barrow JD (2005). Inhomogeneous gravity. nameOfConference

  
  

  DOI: 10.1111/j.1365-2966.2005.08831.x

  
  

  QMRO: https://qmro.qmul.ac.uk/xmlui/handle/123456789/18046

Supervision

This is not an exhaustive list and I would be happy to discuss other project possibilities.