Imperial College London

Prof Fay Dowker

Faculty of Natural SciencesDepartment of Physics

Professor of Theoretical Physics







Mrs Graziela De Nadai-Sowrey +44 (0)20 7594 7843




Huxley BuildingSouth Kensington Campus






BibTex format

author = {Ahmed, SN and Dowker, F and Surya, S},
doi = {1361-6382/aa6bc7},
journal = {Classical and Quantum Gravity},
pages = {1--19},
title = {Scalar field Green functions on causal sets},
url = {},
volume = {34},
year = {2017}

RIS format (EndNote, RefMan)

AB - We examine the validity and scope of Johnston's models for scalar field retarded Green functions on causal sets in 2 and 4 dimensions. As in the continuum, the massive Green function can be obtained from the massless one, and hence the key task in causal set theory is to first identify the massless Green function. We propose that the 2d model provides a Green function for the massive scalar field on causal sets approximated by any topologically trivial 2-dimensional spacetime. We explicitly demonstrate that this is indeed the case in a Riemann normal neighbourhood. In 4d the model can again be used to provide a Green function for the massive scalar field in a Riemann normal neighbourhood which we compare to Bunch and Parker's continuum Green function. We find that the same prescription can also be used for de Sitter spacetime and the conformally flat patch of anti-de Sitter spacetime. Our analysis then allows us to suggest a generalisation of Johnston's model for the Green function for a causal set approximated by 3-dimensional flat spacetime.
AU - Ahmed,SN
AU - Dowker,F
AU - Surya,S
DO - 1361-6382/aa6bc7
EP - 19
PY - 2017///
SN - 0264-9381
SP - 1
TI - Scalar field Green functions on causal sets
T2 - Classical and Quantum Gravity
UR -
UR -
UR -
UR -
VL - 34
ER -