I am a physicist, working mainly on early universe cosmology. In my research, I explore mathematical models for the very early universe, in particular models that try to explain the big bang.

Below is a list of my scientific papers. The e-Print links lead to freely available versions.

In this picture each point represents a possible evolution of the universe. The red lines show more likely universes. Where the lines cross are the most likely universes, which have a rounded-off "no-boundary" geometry.

Delicate curvature bounces in the no-boundary wave function and in the late universe

Jean-Luc Lehners (Potsdam, Max Planck Inst.), Jerome Quintin (U. Waterloo (main) and Perimeter Inst. Theor. Phys.)

e-Print: 2403.15205 [gr-qc]


NUTs, Bolts and Stokes Phenomena in the No-Boundary Wave Function

Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 2402.10501 [gr-qc]


Higher-order gravity, finite action, and a safe beginning for the universe

Jean-Luc Lehners (Potsdam, Max Planck Inst.), K.S. Stelle (Imperial Coll., London)

e-Print: 2312.14048 [hep-th]

DOI: 10.1140/epjp/s13360-024-05125-y

Published in: Eur.Phys.J.Plus 139 (2024), 380


Stability of axion-dilaton wormholes

Caroline Jonas (Leuven U.), George Lavrelashvili (Javakhishvili State U.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 2312.08971 [hep-th]

DOI: 10.1103/PhysRevD.109.086022 (publication)

Published in: Phys.Rev.D 109 (2024) 8, 086022


A small Universe

Jean-Luc Lehners (Potsdam, Max Planck Inst.), Jerome Quintin (U. Waterloo (main) and Perimeter Inst. Theor. Phys.)

e-Print: 2309.03272 [hep-th]

DOI: 10.1016/j.physletb.2024.138488 (publication)

Published in: Phys.Lett.B 850 (2024), 138488


Zoo of axionic wormholes

Caroline Jonas (Potsdam, Max Planck Inst.), George Lavrelashvili (Razmadze Math. Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 2306.11129 [hep-th]

DOI: 10.1103/PhysRevD.108.066012 (publication)

Published in: Phys.Rev.D 108 (2023) 6, 066012


Review of the no-boundary wave function

Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 2303.08802 [hep-th]

DOI: 10.1016/j.physrep.2023.06.002 (publication)

Published in: Phys.Rept. 1022 (2023), 1-82


Allowable complex scalars from Kaluza-Klein compactifications and metric rescalings

Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 2209.14669 [hep-th]

DOI: 10.1103/PhysRevD.107.046004 (publication)

Published in: Phys.Rev.D 107 (2023) 4, 046004


How to create universes with internal flux

Jean-Luc Lehners (Potsdam, Max Planck Inst.), Rahim Leung (Imperial Coll., London), K.S. Stelle (Imperial Coll., London)

e-Print: 2209.08960 [hep-th]

DOI: 10.1103/PhysRevD.107.046006 (publication)

Published in: Phys.Rev.D 107 (2023) 4, 046006


Uses of complex metrics in cosmology

Caroline Jonas (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Jerome Quintin (Potsdam, Max Planck Inst. and Fields Inst., Toronto and U. Waterloo (main))

e-Print: 2205.15332 [hep-th]

DOI: 10.1007/JHEP08(2022)284

Published in: JHEP 08 (2022), 284


Revisiting the no-boundary proposal with a scalar field

Caroline Jonas (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Vincent Meyer (Humboldt U., Berlin and Zurich, ETH)

e-Print: 2112.07986 [hep-th]

DOI: 10.1103/PhysRevD.105.043529 (publication)

Published in: Phys.Rev.D 105 (2022) 4, 043529


Allowable complex metrics in minisuperspace quantum cosmology

Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 2111.07816 [hep-th]

DOI: 10.1103/PhysRevD.105.026022 (publication)

Published in: Phys.Rev.D 105 (2022) 2, 026022


Scalar lumps with two horizons

George Lavrelashvili (Tbilisi State U.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 2109.04180 [gr-qc]

DOI: 10.1103/PhysRevD.105.024051 (publication)

Published in: Phys.Rev.D 105 (2022) 2, 024051


Wave function of simple universes analytically continued from negative to positive potentials

Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 2105.12075 [hep-th]

DOI: 10.1103/PhysRevD.104.063527 (publication)

Published in: Phys.Rev.D 104 (2021) 6, 063527


Scalar lumps with a horizon

George Lavrelashvili (Tbilisi State U. and Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Marc Schneider (Potsdam, Max Planck Inst.)

e-Print: 2104.13403 [hep-th]

DOI: 10.1103/PhysRevD.104.044007 (publication)

Published in: Phys.Rev.D 104 (2021) 4, 044007


Cosmological consequences of a principle of finite amplitudes

Caroline Jonas (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Jerome Quintin (Potsdam, Max Planck Inst.)

e-Print: 2102.05550 [hep-th]

DOI: 10.1103/PhysRevD.103.103525 (publication)

Published in: Phys.Rev.D 103 (2021) 10, 103525


Quantum Circuit Complexity of Primordial Perturbations

Jean-Luc Lehners (Potsdam, Max Planck Inst.), Jerome Quintin (Potsdam, Max Planck Inst.)

e-Print: 2012.04911 [hep-th]

DOI: 10.1103/PhysRevD.103.063527 (publication)

Published in: Phys.Rev.D 103 (2021) 6, 063527


No-boundary solutions are robust to quantum gravity corrections

Caroline Jonas (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 2008.04134 [hep-th]

DOI: 10.1103/PhysRevD.102.123539

Published in: Phys.Rev.D 102 (2020), 123539


Lessons for quantum cosmology from anti–de Sitter black holes

Alice Di Tucci (Potsdam, Max Planck Inst.), Michal P. Heller (NCBJ, Warsaw), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 2007.04872 [hep-th]

DOI: 10.1103/PhysRevD.102.086011

Published in: Phys.Rev.D 102 (2020) 8, 086011


No-boundary prescriptions in Lorentzian quantum cosmology

Alice Di Tucci (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Laura Sberna (Perimeter Inst. Theor. Phys.)

e-Print: 1911.06701 [hep-th]

DOI: 10.1103/PhysRevD.100.123543 (publication)

Published in: Phys.Rev.D 100 (2019) 12, 123543


A Safe Beginning for the Universe?

Jean-Luc Lehners (Potsdam, Max Planck Inst.), K.S. Stelle (Imperial Coll., London)

e-Print: 1909.01169 [hep-th]

DOI: 10.1103/PhysRevD.100.083540

Published in: Phys.Rev.D 100 (2019) 8, 083540


Homogeneous Transitions during Inflation: a Description in Quantum Cosmology

Sebastian F. Bramberger (Potsdam, Max Planck Inst.), Alice Di Tucci (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1907.05782 [gr-qc]

DOI: 10.1103/PhysRevD.101.063501

Published in: Phys.Rev.D 101 (2020) 6, 063501


Quantum Incompleteness of Inflation

Alice Di Tucci (Potsdam, Max Planck Inst.), Job Feldbrugge (Perimeter Inst. Theor. Phys.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Neil Turok (Perimeter Inst. Theor. Phys.)

e-Print: 1906.09007 [hep-th]

DOI: 10.1103/PhysRevD.100.063517

Published in: Phys.Rev.D 100 (2019) 6, 063517


Kerr-NUT-de Sitter as an Inhomogeneous Non-Singular Bouncing Cosmology

Andrés Anabalón (Adolfo Ibanez U.), Sebastian F. Bramberger (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1904.07285 [hep-th]

DOI: 10.1007/JHEP09(2019)096

Published in: JHEP 09 (2019), 096


No-Boundary Proposal as a Path Integral with Robin Boundary Conditions

Alice Di Tucci (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1903.06757 [hep-th]

DOI: 10.1103/PhysRevLett.122.201302

Published in: Phys.Rev.Lett. 122 (2019) 20, 201302


Nonsingular bounces catalyzed by dark energy

Sebastian F. Bramberger (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1901.10198 [hep-th]

DOI: 10.1103/PhysRevD.99.123523

Published in: Phys.Rev.D 99 (2019) 12, 123523


No smooth beginning for spacetime

Jean-Luc Lehners (Potsdam, Max Planck Inst.)

DOI: 10.1142/9789811258251_0005 , 10.1142/S0218271819300052

Published in:, Int.J.Mod.Phys.D 28 (2018) 02, 1930005


Small-Field and Scale-Free: Inflation and Ekpyrosis at their Extremes

Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1807.05240 [hep-th]

DOI: 10.1088/1475-7516/2018/11/001

Published in: JCAP 11 (2018), 001


Unstable no-boundary fluctuations from sums over regular metrics

Alice Di Tucci (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1806.07134 [gr-qc]

DOI: 10.1103/PhysRevD.98.103506

Published in: Phys.Rev.D 98 (2018) 10, 103506


Inconsistencies of the New No-Boundary Proposal

Job Feldbrugge (Perimeter Inst. Theor. Phys.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Neil Turok (Perimeter Inst. Theor. Phys.)

e-Print: 1805.01609 [hep-th]

DOI: 10.3390/universe4100100

Published in: Universe 4 (2018) 10, 100


Spinor driven cosmic bounces and their cosmological perturbations

Shane Farnsworth (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Taotao Qiu (Hua-Zhong Normal U.)

e-Print: 1709.03171 [gr-qc]

DOI: 10.1103/PhysRevD.96.083530

Published in: Phys.Rev.D 96 (2017) 8, 083530


No rescue for the no boundary proposal: Pointers to the future of quantum cosmology

Job Feldbrugge (Perimeter Inst. Theor. Phys.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Neil Turok (Perimeter Inst. Theor. Phys.)

e-Print: 1708.05104 [hep-th]

DOI: 10.1103/PhysRevD.97.023509

Published in: Phys.Rev.D 97 (2018) 2, 023509


No smooth beginning for spacetime

Job Feldbrugge (Perimeter Inst. Theor. Phys.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Neil Turok (Perimeter Inst. Theor. Phys.)

e-Print: 1705.00192 [hep-th]

DOI: 10.1103/PhysRevLett.119.171301

Published in: Phys.Rev.Lett. 119 (2017) 17, 171301


Lorentzian Quantum Cosmology

Job Feldbrugge (Perimeter Inst. Theor. Phys.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Neil Turok (Perimeter Inst. Theor. Phys.)

e-Print: 1703.02076 [hep-th]

DOI: 10.1103/PhysRevD.95.103508

Published in: Phys.Rev.D 95 (2017) 10, 103508


Wavefunction of anisotropic inflationary universes with no-boundary conditions

Sebastian F. Bramberger (Potsdam, Max Planck Inst.), Shane Farnsworth (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1701.05753 [hep-th]

DOI: 10.1103/PhysRevD.95.083513

Published in: Phys.Rev.D 95 (2017) 8, 083513


Quantum Transitions Through Cosmological Singularities

Sebastian F. Bramberger (Potsdam, Max Planck Inst.), Thomas Hertog (Leuven U.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Yannick Vreys (Leuven U.)

e-Print: 1701.05399 [hep-th]

DOI: 10.1088/1475-7516/2017/07/007

Published in: JCAP 07 (2017), 007


Converting entropy to curvature perturbations after a cosmic bounce

Angelika Fertig (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Enno Mallwitz (Potsdam, Max Planck Inst.), Edward Wilson-Ewing (Potsdam, Max Planck Inst.)

e-Print: 1607.05663 [hep-th]

DOI: 10.1088/1475-7516/2016/10/005

Published in: JCAP 10 (2016), 005


Quantum tunneling from paths in complex time

Sebastian F. Bramberger (Potsdam, Max Planck Inst.), George Lavrelashvili (Razmadze Math. Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1605.02751 [hep-th]

DOI: 10.1103/PhysRevD.94.064032

Published in: Phys.Rev.D 94 (2016) 6, 064032


Wormhole creation by quantum tunnelling

Lorenzo Battarra (Potsdam, Max Planck Inst.), George Lavrelashvili (Potsdam, Max Planck Inst. and Razmadze Math. Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1603.08728 [gr-qc]

DOI: 10.1142/9789813226609_0123

Published in:


Nonsingular bouncing cosmology: Consistency of the effective description

Michael Koehn (Pennsylvania U.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Burt Ovrut (Pennsylvania U.)

e-Print: 1512.03807 [hep-th]

DOI: 10.1103/PhysRevD.93.103501

Published in: Phys.Rev.D 93 (2016) 10, 103501


The Non-Minimal Ekpyrotic Trispectrum

Angelika Fertig (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1510.03439 [hep-th]

DOI: 10.1088/1475-7516/2016/01/026

Published in: JCAP 01 (2016), 026


Running of the scalar spectral index in bouncing cosmologies

Jean-Luc Lehners (Potsdam, Max Planck Inst.), Edward Wilson-Ewing (Potsdam, Max Planck Inst.)

e-Print: 1507.08112 [astro-ph.CO]

DOI: 10.1088/1475-7516/2015/10/038

Published in: JCAP 10 (2015), 038


Conflation: a new type of accelerated expansion

Angelika Fertig (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Enno Mallwitz (Potsdam, Max Planck Inst.)

e-Print: 1507.04742 [hep-th]

DOI: 10.1088/1475-7516/2016/08/073

Published in: JCAP 08 (2016), 073


Towards a Solution of the Negative Mode Problem in Quantum Tunnelling with Gravity

Michael Koehn (Pennsylvania U.), George Lavrelashvili (Razmadze Math. Inst. and Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1504.04334 [hep-th]

DOI: 10.1103/PhysRevD.92.023506

Published in: Phys.Rev.D 92 (2015) 2, 023506


New Ekpyrotic Quantum Cosmology

Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1504.02467 [hep-th]

DOI: 10.1016/j.physletb.2015.09.032

Published in: Phys.Lett.B 750 (2015), 242-246


Classical Inflationary and Ekpyrotic Universes in the No-Boundary Wavefunction

Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1502.00629 [hep-th]

DOI: 10.1103/PhysRevD.91.083525

Published in: Phys.Rev.D 91 (2015) 8, 083525


Creation of wormholes by quantum tunnelling in modified gravity theories

Lorenzo Battarra (Potsdam, Max Planck Inst.), George Lavrelashvili (Potsdam, Max Planck Inst. and Razmadze Math. Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1407.6026 [hep-th]

DOI: 10.1103/PhysRevD.90.124015

Published in: Phys.Rev.D 90 (2014) 12, 124015


On the No-Boundary Proposal for Ekpyrotic and Cyclic Cosmologies

Lorenzo Battarra (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1407.4814 [hep-th]

DOI: 10.1088/1475-7516/2014/12/023

Published in: JCAP 12 (2014), 023


On the Creation of the Universe via Ekpyrotic Instantons

Lorenzo Battarra (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1406.5896 [hep-th]

DOI: 10.1016/j.physletb.2015.01.028

Published in: Phys.Lett.B 742 (2015), 167-171


Cosmological Perturbations Through a Non-Singular Ghost-Condensate/Galileon Bounce

Lorenzo Battarra (Potsdam, Max Planck Inst.), Michael Koehn (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Burt A. Ovrut (Pennsylvania U.)

e-Print: 1404.5067 [hep-th]

DOI: 10.1088/1475-7516/2014/07/007

Published in: JCAP 07 (2014), 007


General mechanism for producing scale-invariant perturbations and small non-Gaussianity in ekpyrotic models

Anna Ijjas (Potsdam, Max Planck Inst. and Rutgers U., Piscataway), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Paul J. Steinhardt (Princeton U.)

e-Print: 1404.1265 [astro-ph.CO]

DOI: 10.1103/PhysRevD.89.123520

Published in: Phys.Rev.D 89 (2014) 12, 123520


Non-Canonical Inflation in Supergravity

Rhiannon Gwyn (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1402.5120 [hep-th]

DOI: 10.1007/JHEP05(2014)050

Published in: JHEP 05 (2014), 050


Scalars with Higher Derivatives in Supergravity and Cosmology

Michael Koehn (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Burt A. Ovrut (Pennsylvania U.)

DOI: 10.1007/978-3-319-03774-5_7

Published in: Springer Proc.Phys. 153 (2014), 115-143


Ghost Condensation in \(N=1\) Supergravity

Michael Koehn (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Burt Ovrut (Pennsylvania U.)

DOI: 10.1007/978-3-319-03774-5_9

Published in: Springer Proc.Phys. 153 (2014), 163-178


Ekpyrotic Perturbations With Small Non-Gaussian Corrections

Angelika Fertig (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Enno Mallwitz (Potsdam, Max Planck Inst.)

e-Print: 1310.8133 [hep-th]

DOI: 10.1103/PhysRevD.89.103537

Published in: Phys.Rev.D 89 (2014) 10, 103537


Cosmological super-bounce

Michael Koehn (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Burt A. Ovrut (Pennsylvania U.)

e-Print: 1310.7577 [hep-th]

DOI: 10.1103/PhysRevD.90.025005

Published in: Phys.Rev.D 90 (2014) 2, 025005


Quantum-to-classical transition for ekpyrotic perturbations

Lorenzo Battarra (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1309.2281 [hep-th]

DOI: 10.1103/PhysRevD.89.063516

Published in: Phys.Rev.D 89 (2014) 6, 063516


Zoology of instanton solutions in flat potential barriers

Lorenzo Battarra (Potsdam, Max Planck Inst.), George Lavrelashvili (Razmadze Math. Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1307.7954 [hep-th]

DOI: 10.1103/PhysRevD.88.104012

Published in: Phys.Rev.D 88 (2013), 104012


Planck 2013 results support the cyclic universe

Jean-Luc Lehners (Potsdam, Max Planck Inst.), Paul J. Steinhardt (Harvard-Smithsonian Ctr. Astrophys. and Princeton U. and Princeton U., CTP)

e-Print: 1304.3122 [astro-ph.CO]

DOI: 10.1103/PhysRevD.87.123533

Published in: Phys.Rev.D 87 (2013) 12, 123533


Supersymmetric cubic Galileons have ghosts

Michael Koehn (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Burt Ovrut (Pennsylvania U.)

e-Print: 1302.0840 [hep-th]

DOI: 10.1103/PhysRevD.88.023528

Published in: Phys.Rev.D 88 (2013) 2, 023528


Scalars with higher derivatives in supergravity and cosmology

Jean-Luc Lehners (Potsdam, Max Planck Inst.)

DOI: 10.22323/1.177.0118

Published in: PoS Corfu2012 (2013), 118


Ghost condensate in $N=1$ supergravity

Michael Koehn (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Burt Ovrut (Pennsylvania U.)

e-Print: 1212.2185 [hep-th]

DOI: 10.1103/PhysRevD.87.065022

Published in: Phys.Rev.D 87 (2013) 6, 065022


DBI Inflation in N=1 Supergravity

Michael Koehn (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Burt A. Ovrut (Pennsylvania U.)

e-Print: 1208.0752 [hep-th]

DOI: 10.1103/PhysRevD.86.123510

Published in: Phys.Rev.D 86 (2012), 123510


Negative Modes of Oscillating Instantons

Lorenzo Battarra (Potsdam, Max Planck Inst.), George Lavrelashvili (Razmadze Math. Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1208.2182 [hep-th]

DOI: 10.1103/PhysRevD.86.124001

Published in: Phys.Rev.D 86 (2012), 124001


Higher-Derivative Chiral Superfield Actions Coupled to N=1 Supergravity

Michael Koehn (Potsdam, Max Planck Inst.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Burt A. Ovrut (Pennsylvania U.)

e-Print: 1207.3798 [hep-th]

DOI: 10.1103/PhysRevD.86.085019

Published in: Phys.Rev.D 86 (2012), 085019


Eternal Inflation With Non-Inflationary Pocket Universes

Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1206.1081 [hep-th]

DOI: 10.1103/PhysRevD.86.043518

Published in: Phys.Rev.D 86 (2012), 043518


Cycles in the Multiverse

Matthew C. Johnson (Perimeter Inst. Theor. Phys.), Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1112.3360 [hep-th]

DOI: 10.1103/PhysRevD.85.103509

Published in: Phys.Rev.D 85 (2012), 103509


Diversity in the Phoenix Universe

Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1107.4551 [hep-th]

DOI: 10.1103/PhysRevD.84.103518

Published in: Phys.Rev.D 84 (2011), 103518


Cosmic Bounces and Cyclic Universes

Jean-Luc Lehners (Potsdam, Max Planck Inst.)

e-Print: 1106.0172 [hep-th]

DOI: 10.1088/0264-9381/28/20/204004

Published in: Class.Quant.Grav. 28 (2011), 204004


Supersymmetric Galileons

Justin Khoury (Pennsylvania U.), Jean-Luc Lehners (Potsdam, Max Planck Inst.), Burt A. Ovrut (Pennsylvania U.)

e-Print: 1103.0003 [hep-th]

DOI: 10.1103/PhysRevD.84.043521

Published in: Phys.Rev.D 84 (2011), 043521


Supersymmetric P(X,$\phi$) and the Ghost Condensate

Justin Khoury (Pennsylvania U.), Jean-Luc Lehners (Perimeter Inst. Theor. Phys. and Potsdam, Max Planck Inst.), Burt Ovrut (Pennsylvania U.)

e-Print: 1012.3748 [hep-th]

DOI: 10.1103/PhysRevD.83.125031

Published in: Phys.Rev.D 83 (2011), 125031


Dynamical Selection of the Primordial Density Fluctuation Amplitude

Jean-Luc Lehners (Princeton U., CTP), Paul J. Steinhardt (Princeton U., CTP and Princeton U.)

e-Print: 1008.4567 [hep-th]

DOI: 10.1103/PhysRevLett.106.081301

Published in: Phys.Rev.Lett. 106 (2011), 081301


Ekpyrotic Non-Gaussianity: A Review

Jean-Luc Lehners (Princeton U.)

e-Print: 1001.3125 [hep-th]

DOI: 10.1155/2010/903907

Published in: Adv.Astron. 2010 (2010), 903907


Non-Gaussianity Generated by the Entropic Mechanism in Bouncing Cosmologies Made Simple

Jean-Luc Lehners (Princeton U., CTP), Paul J. Steinhardt (Princeton U., CTP and Princeton U.)

e-Print: 0909.2558 [hep-th]

DOI: 10.1103/PhysRevD.80.103520

Published in: Phys.Rev.D 80 (2009), 103520


Multifield Cosmological Perturbations at Third Order and the Ekpyrotic Trispectrum

Jean-Luc Lehners (Princeton U., CTP), Sebastien Renaux-Petel (APC, Paris)

e-Print: 0906.0530 [hep-th]

DOI: 10.1103/PhysRevD.80.063503

Published in: Phys.Rev.D 80 (2009), 063503


The Return of the Phoenix Universe

Jean-Luc Lehners (Princeton U., CTP), Paul J. Steinhardt (Princeton U., CTP and Princeton U.), Neil Turok (Perimeter Inst. Theor. Phys.)

e-Print: 0910.0834 [hep-th]

DOI: 10.1142/S0218271809015977

Published in: Int.J.Mod.Phys.D 18 (2009), 2231-2235


Non-Gaussianity as a Probe of the Physics of the Primordial Universe and the Astrophysics of the Low Redshift Universe

E. Komatsu (Texas U. and Tokyo U.), N. Afshordi (Perimeter Inst. Theor. Phys.), N. Bartolo (Padua U.), D. Baumann (Harvard U.), J.R. Bond (Toronto U.) et al.

e-Print: 0902.4759 [astro-ph.CO]


Dark Energy and the Return of the Phoenix Universe

Jean-Luc Lehners (Princeton U., CTP), Paul J. Steinhardt (Princeton U., CTP and Princeton U.)

e-Print: 0812.3388 [hep-th]

DOI: 10.1103/PhysRevD.79.063503

Published in: Phys.Rev.D 79 (2009), 063503


Ekpyrotic and Cyclic Cosmology

Jean-Luc Lehners

e-Print: 0806.1245 [astro-ph]

DOI: 10.1016/j.physrep.2008.06.001

Published in: Phys.Rept. 465 (2008), 223-263


Intuitive understanding of non-gaussianity in ekpyrotic and cyclic models

Jean-Luc Lehners (Princeton U., CTP), Paul J. Steinhardt (Princeton U., CTP and Princeton U.)

e-Print: 0804.1293 [hep-th]

DOI: 10.1103/PhysRevD.78.023506 , 10.1103/PhysRevD.79.129902

Published in: Phys.Rev.D 78 (2008), 023506, Phys.Rev.D 79 (2009), 129902 (erratum)


Non-Gaussian density fluctuations from entropically generated curvature perturbations in Ekpyrotic models

Jean-Luc Lehners (Princeton U., CTP), Paul J. Steinhardt (Princeton U., CTP and Princeton U.)

e-Print: 0712.3779 [hep-th]

DOI: 10.1103/PhysRevD.77.063533 , 10.1103/PhysRevD.79.129903

Published in: Phys.Rev.D 77 (2008), 063533, Phys.Rev.D 79 (2009), 129903 (erratum)


Bouncing Negative-Tension Branes

Jean-Luc Lehners (Cambridge U., DAMTP), Neil Turok (Cambridge U., DAMTP)

e-Print: 0708.0743 [hep-th]

DOI: 10.1103/PhysRevD.77.023516

Published in: Phys.Rev.D 77 (2008), 023516


Bouncing and Colliding Branes

Jean-Luc Lehners (Cambridge U., DAMTP)

e-Print: 0708.2633 [hep-th]

DOI: 10.1063/1.2823796

Published in: AIP Conf.Proc. 957 (2007) 1, 337-340


Kaluza-Klein induced supersymmetry breaking for braneworlds in type IIB supergravity

Jean-Luc Lehners (Cambridge U., DAMTP), Paul Smyth (Leuven U.), K.S. Stelle (Imperial Coll., London)

e-Print: 0704.3343 [hep-th]

DOI: 10.1016/j.nuclphysb.2007.08.016

Published in: Nucl.Phys.B 790 (2008), 89-110


Generating ekpyrotic curvature perturbations before the big bang

Jean-Luc Lehners (Cambridge U., DAMTP), Paul McFadden (Amsterdam U.), Neil Turok (Cambridge U., DAMTP), Paul J. Steinhardt (Princeton U.)

e-Print: hep-th/0702153 [hep-th]

DOI: 10.1103/PhysRevD.76.103501

Published in: Phys.Rev.D 76 (2007), 103501


Effective Actions for Heterotic M-Theory

Jean-Luc Lehners (Cambridge U., DAMTP), Paul McFadden (Amsterdam U.), Neil Turok (Cambridge U., DAMTP)

e-Print: hep-th/0612026 [hep-th]

DOI: 10.1103/PhysRevD.76.023501

Published in: Phys.Rev.D 76 (2007), 023501


Colliding Branes in Heterotic M-theory

Jean-Luc Lehners (Cambridge U., DAMTP), Paul McFadden (Amsterdam U.), Neil Turok (Cambridge U., DAMTP)

e-Print: hep-th/0611259 [hep-th]

DOI: 10.1103/PhysRevD.75.103510

Published in: Phys.Rev.D 75 (2007), 103510


Stability of Horava-Witten spacetimes

J.-L. Lehners (Imperial Coll., London), P. Smyth (Imperial Coll., London and Leuven U.), K.S. Stelle (Imperial Coll., London)

e-Print: hep-th/0501212 [hep-th]

DOI: 10.1088/0264-9381/22/13/005

Published in: Class.Quant.Grav. 22 (2005), 2589-2606


D=5 M theory radion supermultiplet dynamics

Jean-Luc Lehners (Imperial Coll., London), K.S. Stelle (Imperial Coll., London)

e-Print: hep-th/0210228 [hep-th]

DOI: 10.1016/S0550-3213(03)00265-7

Published in: Nucl.Phys.B 661 (2003), 273-288