85 citations · 253 across the 31 of their papers we have counts for
8 papers · 1 filter
Graphical Gaussian models associated to a homogeneous graph with permutation symmetries
Piotr Graczyk, Hideyuki Ishi, Bartosz Kołodziejek
We consider multivariate centered Gaussian models for the random vector , whose conditional structure is described by a homogeneous graph and which is invariant…
Pattern recovery by SLOPE
Małgorzata Bogdan, Xavier Dupuis, Piotr Graczyk +4
SLOPE is a popular method for dimensionality reduction in the high-dimensional regression. Indeed some regression coefficient estimates of SLOPE can be null (sparsity) or can be eq…
Pattern recovery and signal denoising by SLOPE when the design matrix is orthogonal
Tomasz Skalski, Piotr Graczyk, Bartosz Kołodziejek +1
Sorted Penalized Estimator (SLOPE) is a relatively new convex regularization method for fitting high-dimensional regression models. SLOPE allows to reduce the model dimens…
Wigner and Wishart Ensembles for graphical models
Hideto Nakashima, Piotr Graczyk
Vinberg cones and the ambient vector spaces are important in modern statistics of sparse models and of graphical models. The aim of this paper is to study eigenvalue distributions…
Model selection in the space of Gaussian models invariant by symmetry
Piotr Graczyk, Hideyuki Ishi, Bartosz Kołodziejek +1
We consider multivariate centered Gaussian models for the random variable , invariant under the action of a subgroup of the group of permutations on $\{1,\ldot…
Wishart laws and variance function on homogeneous cones
Piotr Graczyk, Hideyuki Ishi, Bartosz Kołodziejek
We present a systematic study of Riesz measures and their natural exponential families of Wishart laws on a homogeneous cone. We compute explicitly the inverse of the mean map and…