Publications (26)
Know (better) your neighbour: New HI structures in Messier 33 unveiled by a multiple peak analysis of high-resolution 21-cm data
Laurent Chemin, Claude Carignan, Tyler Foster +1
In our quest to constrain the dynamical and structural properties of Local Group spirals from high-quality interferometric data, we have performed a neutral hydrogen survey in the…
Rational Connectivity and Analytic Contractibility
Morgan Brown, Tyler Foster
Let k be an algebraically closed field of characteristic 0, and let f be a morphism of smooth projective varieties from X to Y over the ring k((t)) of formal Laurent series. We pro…
Canadian Investigations of the Interstellar Medium
Alex S. Hill, Jan Cami, Laura Fissel +10
The interstellar medium mediates galactic evolution as the reservoir of material for future star formation and the repository of energy and matter output by stellar processes. Cana…
Galois actions on analytifications and tropicalizations
Tyler Foster
This paper initiates a research program that seeks to recover algebro-geometric Galois representations from combinatorial data. We study tropicalizations equipped with symmetries c…
Structure and Dynamics of the Milky Way: The Evolving Picture
Tyler Foster, Brendan Cooper
From the inception of radio astronomy, the study of the Interstellar Medium has been both aided and frustrated by one fact: we are right within it! Our embedded perspective is favo…
D-structures and derived Koszul duality for unital operad algebras
Tyler Foster, Po Hu, Igor Kriz
Generalizing a concept of Lipshitz, Ozsváth and Thurs-ton from Bordered Floer homology, we define -structures on algebras of unital operads, which can also be interpreted as a…
Correlations between primes in short intervals on curves over finite fields
Efrat Bank, Tyler Foster
We prove an analogue of the Hardy-Littlewood conjecture on the asymptotic distribution of prime constellations in the setting of short intervals in function fields of smooth projec…
Hahn analytification and connectivity of higher rank tropical varieties
Tyler Foster, Dhruv Ranganathan
We show that the tropicalization of a connected variety over a higher rank valued field is a path connected topological space. This establishes an affirmative answer to a question…
A Noncommutative Version of the Natural Numbers
Tyler Foster
In this note, we construct and study an algebraic system similar to the natural numbers, but with noncommutative addition. The addition we introduce is a binary operation that comm…
G141.2+5.0, a new Pulsar Wind Nebula discovered in the Cygnus Arm of the Milky Way
Roland Kothes, Xiaohui Sun, Wolfgang Reich +1
We report the discovery of the new pulsar wind nebula (PWN) G141.2+5.0 in data observed with the Dominion Radio Astrophysical Observatory's Synthesis Telescope at 1420 MHz. The new…
HI observations of IC 10 with the DRAO synthesis telescope
Brenda Namumba, Claude Carignan, Tyler Foster +1
HI observations of the nearby blue compact dwarf galaxy IC 10 obtained with the Dominion Radio Astrophysical Observatory synthesis telescope (DRAO), for a total integration of $\si…
Two Radio Supernova Remnants Discovered in the Outer Galaxy
Tyler Foster, Brendan Cooper, Wolfgang Reich +2
We report on the discovery of two supernova remnants (SNRs) designated G152.4-2.1 and G190.9-2.2, using Canadian Galactic Plane Survey data. The aims of this paper are, first, to p…
A New Distance to the Supernova Remnant DA 530 Based on HI Absorption of Polarized Emission
Rebecca A. Booth, Roland Kothes, Tom Landecker +4
Supernova remnants (SNRs) are significant contributors of matter and energy to the interstellar medium. Understanding the impact and the mechanism of this contribution requires kno…
HI Kinematics and Mass Distribution of Messier 33
S. Zacharie Kam, Claude Carignan, Laurent Chemin +3
A new deep HI survey of the galaxy Messier 33 is presented, based on observations obtained at the Dominion Radio Astrophysical Observatory. We observe a perturbed outer gas distrib…
Limits of tropicalizations
Tyler Foster, Philipp Gross, Sam Payne
We give general criteria under which the limit of a system of tropicalizations of a scheme over a nonarchimedean field is homeomorphic to the analytification of the scheme. As an a…
Adic tropicalizations and cofinality of Gubler models
Tyler Foster, Sam Payne
We introduce adic tropicalizations for subschemes of toric varieties as limits of Gubler models associated to polyhedral covers of the ordinary tropicalization. Our main result sho…
Logarithmic Picard groups, chip firing, and the combinatorial rank
Tyler Foster, Dhruv Ranganathan, Mattia Talpo +1
Illusie has suggested that one should think of the classifying group of -torsors on a logarithmically smooth curve over a standard logarithmic point as a logarithmic…
Primes in short intervals on curves over finite fields
Efrat Bank, Tyler Foster
We prove an analogue of the Prime Number Theorem for short intervals on a smooth projective geometrically irreducible curve of arbitrary genus over a finite field. A short interval…
HI kinematics and dynamics of Messier 31
Laurent Chemin, Claude Carignan, Tyler Foster
[Abridged] We present a new deep 21-cm survey of the Andromeda galaxy, based on high resolution observations performed with the Synthesis Telescope and the 26-m antenna at DRAO. Th…
Higher configuration operads by way of quiver Grassmannians
Tyler Foster
We introduce a construction that associates, to each finite dimensional k-vector space V, a family of projective k-varieties that comes equipped with the structure of a operad in t…
Deep wide field HI imaging of Messier 31
Laurent Chemin, Claude Carignan, Tyler Foster
We report on preliminary results from a new deep 21-cm survey of the Andromeda galaxy, based on observations performed with the Synthesis Telescope and the 26-m antenna at DRAO. Th…
Extended HI Rotation Curve of M31 using deep DRAO observations
Claude Carignan, Laurent Chemin, Tyler Foster
Carignan et al. (2006) recently presented an extended HI rotation curve (RC) of M31, using single dish observations from the 100m Effelsberg and Green Bank telescopes. These observ…
A Relation Between the Warm Neutral and Ionized Media Observed in the Canadian Galactic Plane Survey
Tyler Foster, Roland Kothes, Joanne Brown
We report on a comparison between 21 cm rotation measure (RM) and the optically-thin atomic hydrogen column density (N_HI) measured towards unresolved extragalactic sources in the…
Degenerations of toric varieties over valuation rings
Tyler Foster, Dhruv Ranganathan
We develop a theory of multi-stage degenerations of toric varieties over finite rank valuation rings, extending the Mumford--Gubler theory in rank one. Such degenerations are const…
Introduction to adic tropicalization
Tyler Foster
This is an expository article on the adic tropicalization of algebraic varieties. We outline joint work with Sam Payne in which we put a topology and structure sheaf of local topol…
Non-Archimedean and tropical theta functions
Tyler Foster, Joseph Rabinoff, Farbod Shokrieh +1
We define a tropicalization procedure for theta functions on abelian varieties over a non-Archimedean field. We show that the tropicalization of a non-Archimedean theta function is…