Tootfinder

Tight Lower Bounds for Block-Structured Integer Programs
Christoph Hunkenschr\"oder, Kim-Manuel Klein, Martin Kouteck\'y, Alexandra Lassota, Asaf Levin
https://arxiv.org/abs/2402.17290

Tight Lower Bounds for Block-Structured Integer Programs
We study fundamental block-structured integer programs called tree-fold and multi-stage IPs. Tree-fold IPs admit a constraint matrix with independent blocks linked together by few constraints in a recursive pattern; and transposing their constraint matrix yields multi-stage IPs. The state-of-the-art algorithms to solve these IPs have an exponential gap in their running times, making it natural to ask whether this gap is inherent. We answer this question affirmative. Assuming the Exponential Tim…

Magnetic fields in the Southern Coalsack and beyond
M. J. F. Versteeg, Y. Angarita, A. M. Magalh\~aes, M. Haverkorn, C. V. Rodrigues, R. Santos-Lima, Koji S. Kawabata
https://arxiv.org/abs/2402.17313

Magnetic fields in the Southern Coalsack and beyond
Starlight polarimetry, when combined with accurate distance measurements, allows for exploration of the three-dimensional structure of local magnetic fields in great detail. We present optical polarimetric observations of stars in and close to the Southern Coalsack, taken from the Interstellar Polarization Survey (IPS). Located in five fields of view approximately $0.3^{o}$ by $0.3^{o}$ in size, these data represent the highest density of optical polarimetric observations in the Southern Coalsa…