Zobrazeno 1 - 10
of 4 486
pro vyhledávání: '"Gray, A D"'
We study several natural decision problems in braid groups and Artin groups. We classify the Artin groups with decidable submonoid membership problem in terms of the non-existence of certain forbidden induced subgraphs of the defining graph. Furtherm
Externí odkaz:
http://arxiv.org/abs/2409.11335
The purpose of this paper is to introduce a new family of semigroups - the free projection-generated regular $*$-semigroups - and initiate their systematic study. Such a semigroup $PG(P)$ is constructed from a projection algebra $P$, using the recent
Externí odkaz:
http://arxiv.org/abs/2406.09109
We use 3D computer modelling to investigate the timescales and radiative output from maser flares generated by the impact of shock-waves on astronomical unit-scale clouds in interstellar and star-forming regions, and in circumstellar regions in some
Externí odkaz:
http://arxiv.org/abs/2404.10741
Autor:
Facchini, Stefano, Testi, Leonardo, Humphreys, Elizabeth, Donckt, Mathieu Vander, Isella, Andrea, Wrzosek, Ramon, Baudry, Alain, Gray, Malcom D., Richards, Anita M. S., Vlemmings, Wouter
The water molecule is a key ingredient in the formation of planetary systems, with the water snowline being a favourable location for the growth of massive planetary cores. Here we present Atacama Large Millimeter/ submillimeter Array data of the rin
Externí odkaz:
http://arxiv.org/abs/2403.00647
Previous work has shown that time-reversal symmetric Weyl semimetals with a quadrupolar arrangement of first-order Weyl nodes exhibit a mixed crystalline-electromagnetic response. For systems with higher order Weyl nodes, which are attached to both s
Externí odkaz:
http://arxiv.org/abs/2308.05796
Autor:
Gray, Robert D., Kambites, Mark
We continue the study of the structure of general subgroups (in particular maximal subgroups, also known as group $\mathcal{H}$-classes) of special inverse monoids. Recent research of the authors has established that these can be quite wild, but in t
Externí odkaz:
http://arxiv.org/abs/2306.17787
Motivated by approaches to the word problem for one-relation monoids arising from work of Adian and Oganesian (1987), Guba (1997), and Ivanov, Margolis and Meakin (2001), we study the submonoid and rational subset membership problems in one-relation
Externí odkaz:
http://arxiv.org/abs/2305.15672
ATOMIUM: Probing the inner wind of evolved O-rich stars with new, highly excited H$_2$O and OH lines
Autor:
Baudry, A., Wong, K. T., Etoka, S., Richards, A. M. S., Muller, H. S. P., Herpin, F., Danilovich, T., Gray, M. D., Wallstrom, S., Gobrecht, D., Khouri, T., Decin, L., Gottlieb, C. A., Menten, K. M., Homan, W., Millar, T. J., Montarges, M., Pimpanuwat, B., Plane, J. M. C., Kervella, P.
Publikováno v:
A&A 674, A125 (2023)
Water and the hydroxyl radical are major constituents of the envelope of O-rich late-type stars. Transitions involving energy levels that are highly excited have been observed in both H$_2$O and OH. These and more recently discovered transitions can
Externí odkaz:
http://arxiv.org/abs/2305.03171
Autor:
Dolinka, Igor, Gray, Robert D.
A prefix monoid is a finitely generated submonoid of a finitely presented group generated by the prefixes of its defining relators. Important results of Guba (1997), and of Ivanov, Margolis and Meakin (2001), show how the word problem for certain one
Externí odkaz:
http://arxiv.org/abs/2304.08084
Autor:
Montargès, M., Cannon, E., de Koter, A., Khouri, T., Lagadec, E., Kervella, P., Decin, L., McDonald, I., Homan, W., Waters, L. B. F. M., Sahai, R., Gottlieb, C. A., Malfait, J., Maes, S., Pimpanuwat, B., Jeste, M., Danilovich, T., De Ceuster, F., Van de Sande, M., Gobrecht, D., Wallström, S. H. J., Wong, K. T., Mellah, I. El, Bolte, J., Herpin, F., Richards, A. M. S., Baudry, A., Etoka, S., Gray, M. D., Millar, T. J., Menten, K. M., Müller, H. S. P., Plane, J. M. C., Yates, J., Zijlstra, A.
Publikováno v:
A&A 671, A96 (2023)
Aims. Through the ATOMIUM project, based on an ALMA large program, we aim to present a consistent view of a sample of 17 nearby cool evolved stars (Aymptotic Giant Branch and red supergiant stars). Methods. Here we present VLT/SPHERE-ZIMPOL polarimet
Externí odkaz:
http://arxiv.org/abs/2301.02081