Bala Rajaratnam


Visiting Professor

H70 - Abercrombie Building
The University of Sydney
NSW 2006 Australia


Bio

Bala is a visiting Professor of Business Analytics at the University of Sydney Business School. His research interests lie broadly in high dimensional statistical inference, machine learning and data science. He has worked on various topics in these fields, including graphical models, high dimensional regression, signal processing, spatio-temporal and environmental modeling, covariance estimation, network analysis, Bayesian methodology and financial engineering. His applied interests lie mainly in using data science and statistics to contemporary research problems in economics and finance, biomedical sciences and environmental sciences.

Selected publications

2015

Journal Articles

Diao P, Guillot D, Khare A, and Rajaratnam B (2015) Differential calculus on graphon space Journal of Combinatorial Theory, Series A, 133, 183-227. [More Information]

Guillot D, and Rajaratnam B (2015) Functions preserving positive definiteness for sparse matrices Transactions of the American Mathematical Society, 367 (1), 627-649.

Guillot D, Khare A, and Rajaratnam B (2015) Complete characterization of Hadamard powers preserving Loewner positivity, monotonicity, and convexity Journal of Mathematical Analysis and Applications, 425 (1), 489-507. [More Information]

Guillot D, Rajaratnam B, and Emile-Geay J (2015) Statistical paleoclimate reconstructions via markov random fields Annals of Applied Statistics, 9 (1), 324-352. [More Information]

Horton D, Johnson N, Singh D, Swain D, Rajaratnam B, and Diffenbaugh N (2015) Contribution of changes in atmospheric circulation patterns to extreme temperature trends Nature, 522 (7557), 465-469. [More Information]

Khare K, Oh S, and Rajaratnam B (2015) A convex pseudolikelihood framework for high dimensional partial correlation estimation with convergence guarantees Journal of the Royal Statistical Society Series B, 77 (4), 803-825. [More Information]

Rahman K, Gorelick S, Dennedy-Frank J, Yoon J, and Rajaratnam B (2015) Declining rainfall and regional variability changes in Jordan Water Resources Research, 51 (5), 3828-3835. [More Information]

Rajaratnam B, Romano J, Tsiang M, and Diffenbaugh N (2015) Debunking the climate hiatus Climatic Change, 133 (2), 129-140. [More Information]

Tingley M, Craigmile P, Haran M, Li B, Mannshardt E, and Rajaratnam B (2015) On discriminating between GCM forcing configurations using Bayesian reconstructions of late-holocene temperatures Journal of Climate, 28 (20), 8264-8281. [More Information]

Wang J, Emile-Geay J, Guillot D, McKay N, and Rajaratnam B (2015) Fragility of reconstructed temperature patterns over the Common Era: Implications for model evaluation Geophysical Research Letters, 42 (17), 7162-7170. [More Information]

2014

Journal Articles

Janson L, and Rajaratnam B (2014) A methodology for robust multiproxy paleoclimate reconstructions and modeling of temperature conditional quantiles Journal of the American Statistical Association, 109 (505), 63-77. [More Information]

Li T, Gao C, Xu M, and Rajaratnam B (2014) Detecting the impact area of BP deepwater horizon oil discharge: An analysis by time varying coefficient logistic models and boosted trees Computational Statistics, 29 (1-2), 141-157. [More Information]

Rajaratnam M, Rajaratnam B, and Rajaratnam K (2014) A novel equity valuation and capital allocation model for use by long-term value-investors Journal of Banking & Finance, 49, 483-494. [More Information]

Singh D, Tsiang M, Rajaratnam B, and Dienbaugh N (2014) Observed changes in extreme wet and dry spells during the south Asian summer monsoon season Nature Climate Change, 4 (6), 456-461. [More Information]

Wang J, Emile-Geay J, Guillot D, Smerdon J, and Rajaratnam B (2014) Evaluating climate field reconstruction techniques using improved emulations of real-world conditions Climate of the Past, 10 (1), 1-19. [More Information]

Yoon S, Assimes T, Quertermous T, Hsiao C, Chuang L, Hwu C, Rajaratnam B, and Olshen R (2014) Insulin resistance: Regression and clustering PloS One, 9 (6), 1-12. [More Information]

2013

Journal Articles

Guillot D, Khare A, and Rajaratnam B (2013) The critical exponent conjecture for powers of doubly nonnegative matrices Linear Algebra and its Applications, 439 (8), 2422-2427. [More Information]

Rajaratnam B, and Salzman J (2013) Best permutation analysis Journal of Multivariate Analysis, 121, 193-223. [More Information]

Rolfs B, and Rajaratnam B (2013) A note on the lack of symmetry in the graphical lasso Computational Statistics and Data Analysis, 57 (1), 429-434. [More Information]

Singh D, Tsiang M, Rajaratnam B, and Diffenbaugh N (2013) Precipitation extremes over the continental United States in a transient, high-resolution, ensemble climate model experiment Journal of Geophysical Research: Atmospheres, 118 (13), 7063-7086. [More Information]

Won J, Lim J, Kim S, and Rajaratnam B (2013) Condition-number-regularized covariance estimation Journal of the Royal Statistical Society Series B, 75 (3), 427-450. [More Information]

2012

Journal Articles

Ben-David E, and Rajaratnam B (2012) Positive definite completion problems for Bayesian networks SIAM Journal on Matrix Analysis and Applications, 33 (2), 617-638. [More Information]

Guillot D, and Rajaratnam B (2012) Retaining positive definiteness in thresholded matrices Linear Algebra and its Applications, 436 (11), 4143-4160. [More Information]

Hero A, and Rajaratnam B (2012) Hub discovery in partial correlation graphs IEEE Transactions on Information Theory, 58 (9), 6064-6078. [More Information]

Khare K, and Rajaratnam B (2012) Sparse matrix decompositions and graph characterizations Linear Algebra and its Applications, 437 (3), 932-947. [More Information]

Olshen R, and Rajaratnam B (2012) Successive standardization of rectangular arrays Algorithms, 5 (1), 98-112. [More Information]

Tingley M, Craigmile P, Haran M, Li B, Mannshardt E, and Rajaratnam B (2012) Piecing together the past: Statistical insights into paleoclimatic reconstructions Quaternary Science Reviews, 35, 1-22. [More Information]

2011

Journal Articles

Craigmile P, and Rajaratnam B (2011) Discussion of: A statistical analysis of multiple temperature proxies: Are reconstructions of surface temperatures over the last 1000 years reliable? Annals of Applied Statistics, 5 (1), 88-90. [More Information]

Hero A, and Rajaratnam B (2011) Large-scale correlation screening Journal of the American Statistical Association, 106 (496), 1542-1550. [More Information]

Malouche D, and Rajaratnam B (2011) Gaussian covariance faithful Markov trees Journal of Probability and Statistics, 2011, 1-10. [More Information]

Selected grants