Publications

Extrapolating the projected potential of gravitational lens models: property-preserving degeneracies
Liesenborgs, J., Perera, D., Williams, L.L.R. 2024, MNRAS

Free-Form and Hybrid Lens Models for SDSS J1004+4112: Substructure and Central Image Time Delay Constraints
Perera, D., Williams, L.L.R., Liesenborgs, J., Ghosh, A., Saha, P. 2024, MNRAS, 527, 2639

Flashlights: Properties of Highly Magnified Images Near Cluster Critical Curves in the Presence of Dark Matter Subhalos
Williams, L.L.R., Kelly, P.L., Treu, T., Amruth, A., Diego, J.M., Li, S.-K., Meena, A.K., Zitrin, A., Broadhurst, T.J. 2024, ApJ, 961, 200

BUFFALO/Flashlights: Constraints on the abundance of lensed supergiant stars in the Spock galaxy at redshift 1
Diego, J.M., et al. 2024, A&A, 681, 124

Strong Lensing by Galaxy Clusters
Natarajan, P, Williams, L.L.R., Bradac, M., Grillo, C., Ghosh, A., Sharon, K., Wagner, J. 2024, MNRAS, Space Science Reviews, Topical Collection "Strong Gravitational Lensing", eds. J. Wambsganss et al., SSRv, 200, 19

Essentials of Strong Gravitational Lensing
Saha, P., Sluse, D., Wagner, J., Williams, L.L.R. 2024, Space Science Reviews, Topical Collection "Strong Gravitational Lensing", eds. J. Wambsganss et al., SSRv, 220, 12

Strong Lensing by Galaxies
Shajib, A.J., Vernardos, G., Collett, T.E., Motta, V., Sluse, D., Williams, L.L.R., Saha, P., Birrer, S., Spiniello, C., Treu, T. 2023, Space Science Reviews, Topical Collection "Strong Gravitational Lensing", eds. J. Wambsganss et al.

What multiple images say about the large-scale mass maps of galaxy clusters
Lasko, K., Williams, L.L.R., Ghosh, A. 2023, MNRAS, 525, 5423

Flashlights: An off-caustic lensed star at redshift z = 1.26 in Abell 370
Meena, A.K., Chen, W., Zitrin, A., Kelly, P.L., Golubchik, M., Zhou, R., Amruth, A., Broadhurst, T., Diego, J.M., Filippenko, A.V., Li, S.-K., Oguri, M., Smith, N., Williams, L.L.R. 2023, MNRAS, 521, 522

Constraints on the Inner Regions of Lensing Galaxies from Central Images using a Recent AGN Offset Distribution
Perera, D., Williams, L.L.R., Scarlata, C. 2023, MNRAS, 522, 1863

Constraints on the Hubble Constant from Supernova Refsdal's Reappearance
Kelly, P.L. et al. 2023, Science, 380, 1322

An Excursion into the Core of the Cluster Lens Abell 1689
Agniva Ghosh, Dominic Adams, Liliya L. R. Williams, Jori Liesenborgs, Anahita Alavi, Claudia Scarlata. 2023, MNRAS, 525, 2519

Statistical Mechanics of Collisionless Orbits. V. The approach to equilibrium for idealized self-gravitating systems
Williams, L.L.R., Hjorth, J., 2022, ApJ, 937, 67

Bridging the Gap Between Simply Parametrized and Free-Form Pixelated Models of Galaxy Lenses: The Case of WFI 2033-4723 Quad
Barrera, B., Williams, L.L.R., Coles, J.P., Denzel, P. 2021, OJAp, 4E, 12

Further support for a trio of mass-to-light deviations in Abell 370: free-form Grale lens inversion using BUFFALO strong lensing data
Agniva Ghosh, Liliya L. R. Williams, Jori Liesenborgs, et al. 2021, MNRAS, 506, 6144

Galaxy-lens determination of H0: the effect of the ellipse+shear modeling assumption
Gomer, M.R., Williams, L.L.R., 2021. MNRAS, 504, 1340

Exotic Image Formation in Strong Gravitational Lensing by Clusters of Galaxies -- II: Uncertainties
Ashish Kumar Meena, Agniva Ghosh, J. S. Bagla, L. L. R. Williams. 2021, MNRAS, 506, 1526

The Hubble constant from eight time-delay galaxy lenses
Denzel, P., Coles, J.P., Saha, P., Williams, L.L.R. 2021, MNRAS, 501, 784

Time Delay Lens modelling Challenge: II. Results
Ding, X. et al. 2021, MNRAS, 503, 1096

Two-component mass models of the lensing galaxy in the quadruply imaged supernova iPTF16geu
Liliya L. R. Williams, David Zegeye. 2020, Open Journal of Astroph., 3E, 10

Free-form Grale lens inversion of galaxy clusters with up to 1000 multiple images
Agniva Ghosh, Liliya L. R. Williams, Jori Liesenborgs. 2020, MNRAS, 494, 3998

Extended lens reconstructions with Grale: exploiting time-domain, substructural and weak-lensing information
Jori Liesenborgs, Liliya L. R. Williams, Jenny Wagner, Sven De Rijcke. 2020, MNRAS, 494, 3253

Galaxy-lens determination of H0: constraining density slope in the context of the mass sheet degeneracy
Gomer, M.R., Williams, L.L.R., 2020, JCAP, 11, 045

The BUFFALO HST Survey
Steinhardt, C.L. et al. 2020, ApJS, 247, 64

Power law pseudo phase-space density profiles of dark matter halos: fluke of physics?
A. Arora, L.L.R. Williams. 2020, ApJ, 893, 53

Image Flux Ratios of Gravitationally Lensed HS 0810+2554 with High Resolution Infrared Imaging
Terry Jay Jones, Liliya L. R. Williams, Steve Ertel, Philip M. Hinz, Amali Vaz, Shane Walsh, Ryan Webster. 2019, AJ, 158, 237

Model-independent and model-based local lensing properties of B0128+437 from resolved quasar images
Jenny Wagner, Liliya L. R. Williams. 2019, A&A, 635, 86

Free-form Grale reconstruction of Abell 2744: robustness of uncertainties against changes in lensing data
Sebesta, K., Williams, L.L.R., Liesenborgs, J., Medezinski, E., Okabe, N. 2019, MNRAS, 488, 3251

Searching for Highly Magnified Stars at Cosmological Distances: Discovery of a Redshift 0.94 Blue Supergiant in Archival Images of the Galaxy Cluster MACS J0416.1-2403
W. Chen, P.L. Kelly, J.M. Diego, M. Oguri, L.L.R. Williams, et al. 2019, ApJ, 881, 8

The role of multiple images and model priors in measuring H0 from supernova Refsdal in galaxy cluster MACS J1149.5+2223
Williams, L.L.R., Liesenborgs, J. 2019, MNRAS, 482, 5666

Testing the uniqueness of gravitational lens mass models
Walls, Levi G., Williams, Liliya L. R. 2018, MNRAS, 481, 655

The impact of ΛCDM substructure and baryon-dark matter transition on the image positions of quad galaxy lenses
Gomer, Matthew R; Williams, Liliya L. R. 2018, MNRAS, 475, 1987

Evidence for the line of sight structure in the largest Hubble Frontier Field cluster, MACSJ0717.5+3745
Williams, Liliya L. R., Sebesta, Kevin, Liesenborgs, Jori. 2018, MNRAS, 480, 3140

Dynamics of merging: Post-merger mixing and relaxation of an Illustris galaxy
Anthony M. Young, Liliya L. R. Williams, Jens Hjorth. 2018, JCAP, 02, 033

Dark matter dynamics in Abell 3827: new data consistent with standard Cold Dark Matter
R. Massey, D. Harvey, J. Liesenborgs, J. Richard, S. Stach, M. Swinbank, P. Taylor, L.L.R. Williams, D. Clowe, F. Courbin, A. Edge, H. Israel, M. Jauzac, R. Joseph, E. Jullo, T.D. Kitching, A. Leonard, J. Merten, D. Nagai, J. Nightingale, James; A. Robertson, L.J. Romualdez, P. Saha, R. Smit, S. Ieng Tam, E. Tittley. 2018, MNRAS, 477, 669

Two Peculiar Fast Transients in a Strongly Lensed Host Galaxy
S. A. Rodney, I. Balestra, M. Bradac, G. Brammer, T. Broadhurst, G. B. Caminha, G. Chirivi, J. M. Diego, A. V. Filippenko, R. J. Foley, O. Graur, C. Grillo, S. Hemmati, J. Hjorth, A. Hoag, M. Jauzac, S. W. Jha, R. Kawamata, P. L. Kelly, C. McCully, B. Mobasher, A. Molino, M. Oguri, J. Richard, A. G. Riess, P. Rosati, K. B. Schmidt, J. Selsing, K. Sharon, L.-G. Strolger, S. H. Suyu, T. Treu, B. J. Weiner, L. L. R. Williams, A. Zitrin. 2018, NatAs, 2, 324

Dark matter under the microscope: Constraining compact dark matter with caustic crossing events
Jose M. Diego, Nick Kaiser, Tom Broadhurst, Patrick L. Kelly, Steve Rodney, Takahiro Morishita, Masamune Oguri, Timothy W. Ross, Adi Zitrin, Mathilde Jauzac, Johan Richard, Liliya Williams, Jesus Vega, Brenda Frye, Alexei V. Filipenko. 2018, ApJ, 857, 25

The Frontier Fields Lens Modeling Comparison Project
M. Meneghetti, P. Natarajan, D. Coe, E. Contini, G. De Lucia, C. Giocoli, A. Acebron, S. Borgani, M. Bradac, J. M. Diego, A. Hoag, M. Ishigaki, T. L. Johnson, E. Jullo, R. Kawamata, D. Lam, M. Limousin, J. Liesenborgs, M. Oguri, K. Sebesta, K. Sharon, L. L. R. Williams, A. Zitrin. 2017, MNRAS, 472, 3177

Lens Models Under the Microscope: Comparison of Hubble Frontier Field Cluster Magnification Maps
Priewe, J., Williams, L. L. R., Liesenborgs, J., Coe, D., Rodney, S. A. 2017, MNRAS, 465, 1030

Ubiquity of density slope oscillations in the central regions of galaxy and cluster-sized systems
Young, A. M., Williams, L. L. R., Hjorth, J. 2016, JCAP, 5, 10

Testing DARKexp against energy and density distributions of Millennium-II halos
Nolting, C., Williams, L.L.R., Boylan-Kolchin, M., Hjorth, J. 2016, JCAP, 9, 42

Quantifying substructures in Hubble Frontier Field clusters: comparison with LCDM simulations
Mohammed, I., Saha, P., Williams, L.L.R., Liesenborgs, J. Sebesta, K. 2016, MNRAS, 459, 1698

Testing light-traces-mass in Hubble Frontier Fields Cluster MACS-J0416.1-2403
Sebesta, K., Williams, L.L.R., Mohammed, I., Saha, P., Liesenborgs, J. 2016, MNRAS, 461, 2126

Non-universality of dark-matter halos: cusps, cores and the central potential
Hjorth, J., Williams, L.L.R., Wojtak, R., McLaughlin. M. 2015, ApJ, 811, 2

Illuminating a Dark Lens : A Type Ia Supernova Magnified by the Frontier Fields Galaxy Cluster Abell 2744
Rodney, S. A., Patel, B., Scolnic, D., Foley, R. J., Molino, A., Brammer, G., Jauzac, M., Bradac, M., Broadhurst, T., Coe, D., Diego, J. M., Graur, O., Hjorth, J., Hoag, A., Jha, S. W., Johnson, T. L., Kelly, P., Lam, D., McCully, C., Medezinski, E., Meneghetti, M., Merten, J., Richard, J., Riess, A., Sharon, K., Strolger, L.-G., Treu, T., Wang, X., Williams, L. L. R., Zitrin, A. 2015, ApJ, 811, 70

Model-free analysis of quadruply imaged gravitationally lensed systems and substructured galaxies
Woldensenbet, A.G., Williams, L.L.R. 2015, MNRAS, 454, 862

The behaviour of dark matter associated with 4 bright cluster galaxies in the 10kpc core of Abell 3827
Massey, R., Williams, L.L.R., et al. 2015, MNRAS, 449, 3393

Mass-Galaxy offsets in Abell 3827, 2218 and 1689: intrinsic properties or line-of-sight substructures?
Mohammed, I., Liesenborgs, J., Saha, P., Williams, L.L.R. 2014, MNRAS, 439, 2651

Statistical Mechanics of Collisionless Orbits. IV. Distribution of Angular Momentum
Williams, L.L.R., Hjorth, J., Wojtak, R. 2014, ApJ, 783, 13

Collisionless dynamics in Globular Clusters
Williams, L.L.R., Barnes, E.I., Hjorth, J. 2012, MNRAS, 423, 3589

Entropy Production in Collisionless Systems. II. Arbitrary Phase-Space Occupation Numbers
Barnes, E.I., Williams, L.L.R. 2012, ApJ, 748, 144

Surface Brightness and Intrinsic Luminosity of Ellipticals
Dhar, B.K., Williams, L.L.R., 2012, MNRAS, 427, 204

The Fundamental Surface of Quad Lenses
Woldesenbet, A.G., Williams, L.L.R. 2012, MNRAS, 420, 2944

Light/Mass Offsets in the Lensing Cluster Abell 3827: Evidence for Collisional Dark Matter?
Williams, L.L.R., Saha, P. 2011, MNRAS, 415, 448

Entropy Production in Collisionless Systems. I. Large Phase-Space Occupation Numbers
Barnes, E.I., Williams, L.L.R. 2011, ApJ, 728, 136

Statistical Mechanics of Collisionless Orbits. III. Comparison with N-body Simulations
Williams, L.L.R., Hjorth, J., Wojtak, R. 2010, ApJ, 725, 282

Statistical Mechanics of Collisionless Orbits. II. Structure of Halos
Williams, L.L.R., Hjorth, J. 2010, ApJ, 722, 856

Statistical Mechanics of Collisionless Orbits. I. Origin of Central Cusps in Dark-matter Halos
Hjorth, J., Williams, L.L.R. 2010, ApJ, 722, 851

Understanding micro-image configurations in quasar microlensing
Saha, P., Williams, L.L.R., 2011, MNRAS, 411, 1671

Surface mass density of the Einasto family of dark matter haloes: are they Sersic-like?
Dhar, B,K., Williams, L.L.R., 2010, MNRAS, 405, 340

The Radial Orbit Instability in Collisionless N-Body Simulations
Barnes, E.I., P.A. Lanzel, L.L.R. Williams. 2009, ApJ, 704, 372

Dark Matter Angular Momentum Profile from the Jeans Equation
Kasper B. Schmidt, Steen H. Hansen, Jin H. An, Liliya L. R. Williams, Andrea V. Macci'o. 2009, ApJ, 694, 893

Lensed Image Angles: New Statistical Evidence for Substructure (better quality figures: here)
L.L.R. Williams, P. Foley, D. Farnsworth, J. Belter. 2008, ApJ, 685, 725

The Role of the Radial Orbit Instability in the Dark Matter Halo Formation and Structure
J.M. Bellovary, J.J. Dalcanton, A. Babul, T.R. Quinn, R.W. Maas, C.G. Austin, L.L.R. Williams, and E.I. Barnes. 2008, ApJ.

Extragalactic Radio Sources and the WMAP Cold Spot
Lawrence Rudnick, Shea Brown, Liliya L. R. Williams. 2008, ApJ.

Meso-structure in three strong-lensing systems
P. Saha, L.L.R. Williams, I. Ferreras. 2007, ApJ.

Velocity Distributions from Nonextensive Thermodynamics
Eric I. Barnes, Liliya L. R. Williams, Arif Babul, Julianne J. Dalcanton. 2007, ApJ.

Two strong-lensing clusters confront universal dark-matter profiles
P. Saha, J.I. Read, L.L.R. Williams. 2006, ApJ.

Density Profiles of Collisionless Equilibria. II. Anisotropic Spherical Systems
Eric I. Barnes, Liliya L. R. Williams, Arif Babul, Julianne J. Dalcanton. 2007, ApJ, 654, 814

Gravitational lensing model degeneracies: Is steepness all-important?
P. Saha, L.L.R. Williams. 2006, ApJ.

The Hubble time inferred from 10 time-delay lenses
P. Saha, J. Coles, A.V. Maccio', L.L.R. Williams. 2006

Density Profiles of Collisionless Equilibria. I. Spherical Isotropic Systems
Eric I. Barnes, Liliya L. R. Williams, Arif Babul, Julianne J. Dalcanton. 2006, ApJ, 643, 797

Scalelengths in Dark Matter Halos
Eric I. Barnes, Liliya L. R. Williams, Arif Babul, Julianne J. Dalcanton. 2005, ApJ, 634, 775

Galaxy-Quasar correlations between APM galaxies and Hamburg-ESO QSOs
Joshua G. Nollenberg, Liliya L.R. Williams. 2005

Semi-analytical dark matter halos and the Jeans equation
Crystal G. Austin, Liliya L.R. Williams, Eric I. Barnes, Arif Babul, Julianne J. Dalcanton. 2005, ApJ, 634, 756

Stellar and total mass in early-type lensing galaxies
Ignacio Ferreras, Prasenjit Saha, Liliya L. R. Williams. 2005

Models of the Giant Quadruple Quasar SDSS J1004+4112
L.L.R. Williams, P. Saha. 2004, AJ, to appear in January 2005 issue

Weak lensing of the high redshift SNIa sample
L.L.R. Williams, J. Song. 2004, MNRAS, 351, 1387

A portable modeler of lensed quasars
P. Saha, L.L.R. Williams. 2004, AJ, 127, 2604

Investigating the origins of dark matter halo profiles
L.L.R. Williams, A. Babul, J.J. Dalcanton. 2004, ApJ, 604, 18

Is B1422+231 a Golden Lens?
S. Raychaudhury, P. Saha, L.L.R. Williams. 2003, AJ, 126, 29

Determination of reddening and extiction due to dust in APM galaxy clusters
J.G. Nollenberg, L.L.R. Williams, S.J. Maddox. 2003, AJ, 125, 2927

Qualitative Theory for Lensed QSOs
P. Saha, L.L.R. Williams. 2003, AJ, 125, 2769

Angular Distribution of Gamma-ray Bursts and Weak Lensing
L.L.R. Williams, N. Frey. 2003, ApJ, 583, 594

Beware the Non-Uniqueness of Einstein Rings
P. Saha, L.L.R. Williams. 2001, AJ, 122, 585

Pixelated Lenses and Estimates of H_0 from Time-delay Quasars
L.L.R. Williams, P.Saha. 2000, AJ, 119, 439

Large Scale QSO-Galaxy Correlations and Weak Lensing
L.L.R. Williams. 2000, ApJ, 535, 37

Weak Lensing Induced Correlations between 1Jy QSOs and APM galaxies on Angular Scales of a Degree
D.J. Norman, L.L.R. Williams. 2000, AJ, 119, 2060

The core structure of Galaxy Clusters from Gravitational Lensing
L.L.R. Williams, J.F. Navarro, M. Bartelmann. 1999, ApJ, 527, 535

Non-parametric Reconstruction of Abell 2218 from Combined Weak and Strong Lensing
H.M. AbdelSalam, P. Saha, L.L.R. Williams. 1998, AJ, 116, 1541

Angular correlations between LBQS and APM: Weak Lensing by the Large Scale Structure
L.L.R. Williams, M.J. Irwin. 1998, MNRAS, 298, 378

Measurement of the Hubble Constant Via Gravitational Lensing - A Review of the Jodrell Bank ``Golden Lenses'' Workshop
L.L.R. Williams, P.L. Schechter, 1997, Astronomy & Geophysics (a journal of the RAS), Vol. 38 Issue 5, 10

Non-parametric Reconstruction of Cluster Mass Distribution from Strong Lensing: Modelling Abell 370
H.M. AbdelSalam, P. Saha, L.L.R. Williams. 1997, MNRAS, 294, 734

Image Separation vs. Redshift of Lensed QSOs: Implications for Galaxy Mass Profiles
L.L.R. Williams. 1997, MNRAS, 292, L27

Non-parametric reconstruction of the galaxy lens in PG1115+080
P. Saha, L.L.R. Williams. 1997, MNRAS, 292,148

Undistorted Lensed Images in Galaxy Clusters
L.L.R. Williams, G.F.Lewis. 1997, MNRAS, 294, 299

Distortion of Gamma-Ray Burst Light Curves by Gravitational Microlensing
L.L.R. Williams, R.A.M.J. Wijers, MNRAS, 286, L11

The Giant Proto-Galaxy cB58; an Artifact of Gravitational Lensing?
L.L.R. Williams, G.F.Lewis. 1996, MNRAS, 281, L35

Is the Rapid Radio Variability Seen in PKS 0537-441 Due To Microlensing?
G.F.Lewis, L.L.R. Williams. 1996, MNRAS, 287, 155

The Effect of Weak Gravitational Lensing on the Angular Distribution of Gamma-Ray Bursts
L.L.R. Williams. 1996, ApJ, 472, 497

Improper Motions in Lensed QSOs
L.L.R. Williams, P. Saha. 1995, AJ, 110, 1471

Statistical Association of QSOs with Foreground Galaxy Clusters
L.L. Rodrigues-Williams, C.J. Hogan. 1994, AJ, 107, 451

Absorption-line Profiles in a Companion Spectrum of a Mass-losing Cool Supergiant
L.L. Rodrigues, E. Bohm-Vitense. 1992, ApJ, 401, 695

Test Particle Orbits in a Roche Model of a Semidetached Binary: An Attempt to Explain Gamma-Ray Bursts
L.L. Rodrigues. 1989, AJ, 98, 2280