Tootfinder

A Bivariate DAR($1$) model for ordinal time series
Anna Nalpantidi, Dimitris Karlis
https://arxiv.org/abs/2510.05680 https://arxiv.org/pdf/2510.05680

A Bivariate DAR($1$) model for ordinal time series
We present a bivariate vector valued discrete autoregressive model of order $1$ (BDAR($1$)) for discrete time series. The BDAR($1$) model assumes that each time series follows its own univariate DAR($1$) model with dependent random mechanisms that determine from which component the current status occurs and dependent innovations. The joint distribution of the random mechanisms which are expressed by Bernoulli vectors are proposed to be defined through copulas. The same holds for the joint distr…

HET/HPF observations of Helium in warm, hot, and ultra-hot Jupiters
Jaume Orell-Miquel, Kyra Sampson, Caroline V. Morley, William D. Cochran, Girish M. Duvvuri, Daniel M. Krolikowski, Suvrath Mahadevan, Quang H. Tran
https://arxiv.org/abs/2509.06847

HET/HPF observations of Helium in warm, hot, and ultra-hot Jupiters
The near-infrared helium triplet line is a powerful tool for studying atmospheric escape processes of close-in exoplanets, especially irradiated gas giants. Line profile fitting provides direct insight into the mechanisms driving atmospheric mass loss of close-in, Jupiter-sized planets. We present high-resolution transmission spectroscopy results for the helium triplet line of sixteen gas giants ($R_{\rm p} > 0.5 R_{\rm Jup}$). These observations are part of an extensive helium survey conducted…