angsamica M. Osorno

Associate Professor of Mathematics
Department of Mathematics and Statistics
Reed College
Office: L305
Email: aosorno at reed dot edu

Andrew Blumberg, Mike Hill, Kyle Ormsby, Constanze Roitzheim and I wrote an article for Notices of the AMS introducing homotopical combinatorics.

Nick Gurski, Niles Johnson and I wrote an article for Notices of the AMS outlining our research on the stable homotopy hypothesis.

I do research in algebraic topology. I am particularly interested in higher category theory and its connections with higher K-theory. In 2010, I got my PhD at MIT with Mark Behrens. From 2010 to 2013, I was a postdoc at the University of Chicago working with Peter May.

I am an editor for Orbita Mathematicae and Homology, Homotopy and Applications.

Teaching

Spring 2025: MATH 112 - Intro to Analysis

Spring 2025: MATH 113 - Discrete Structures

Fall 2024: MATH 201 - Linear Algebra

Fall 2024: MATH 412 - Topics in Algebra: Galois Theory

Spring 2024: MATH 113 - Discrete Structures

Spring 2023: MATH 113 - Discrete Structures

Spring 2023: MATH 342 - Topology

Fall 2022: MATH 113 - Discrete Structures

Spring 2022: MATH 201 - Linear Algebra

Spring 2022: MATH 442 - Algebraic Topology

Fall 2021: MATH 201 - Linear Algebra

Spring 2020: MATH 201 - Linear Algebra

Spring 2019: MATH 201 - Linear Algebra

Fall 2018: MATH 113 - Discrete Structures

Fall 2018: MATH 341 - Topics in Geometry

Spring 2018: MATH 201 - Linear Algebra

Spring 2018: MATH 342 - Topology

Fall 2017: MATH 201 - Linear Algebra

Fall 2017: MATH 412 - Topics in Algebra: Representation Theory

Spring 2016: MATH 212 - Multivariable Calculus II

Fall 2015: MATH 211 - Multivariable Calculus I

Fall 2015: MATH 331 - Linear Algebra

Spring 2015: MATH 112 - Intro to Analysis

Spring 2015: MATH 342 - Topology

Fall 2014: MATH 111 - Calculus

Fall 2014: MATH 211 - Multivariable Calculus I

Fall 2013: MATH 111 - Calculus

Publications

Preprints:

Uniquely compatible transfer systems for cyclic groups of order p^rq^s
(with Kristen Mazur, Constanze Roitzheim, Rekha Santhanam, Danika Van Niel and Valentina Zapata Castro)
PDF
Equivariant infinite loop space theory, I. The space level story
(with J. Peter May and Mona Merling)
PDF

Research publications:

The symmetric monoidal 2-category of permutative categories
(with Nick Gurski and Niles Johnson). High. Struct. 8, no. 1, 244-320, 2024.
PDF
Model structures on finite total orders
(with Scott Balchin, Kyle Ormsby, and Constanze Roitzheim). Math. Z. 304, no. 3, Paper No. 40, 35 pp, 2023.
PDF
Multiplicative equivariant K-theory and the Barratt-Priddy-Quillen theorem
(with Bert Guillou, J. Peter May, and Mona Merling). Adv. Math. 414, Paper No. 108865, 111 pp, 2023.
PDF
Saturated and linear isometric transfer systems for cyclic groups of order p ^mqⁿ
(with Usman Hafeez, Peter Marcus, and Kyle Ormsby) Topology Appl., 317, Paper No. 108162, 20 pp., 2022.
PDF.
Self-duality of the lattice of transfer systems via weak factorization systems
(with Evan Franchere, Kyle Ormsby, Weihang Qin, and Riley Waugh). Homology Homotopy Appl. 24, no. 2, 115-134, 2022.
PDF
2-categorical opfibrations, Quillen's Theorem B, and S^-1S
(with Nick Gurski and Niles Johnson). New York J. Math. 27, 1009-1059, 2021.
PDF
Biased permutative equivariant categories
(with Kayleigh Bangs, Skye Binegar, Young Kim, Kyle Ormsby, David Tamas-Parris, Livia Xu). Homology Homotopy Appl. 23, no. 1, 77-100, 2021.
PDF
Comparison of Waldhausen constructions
(with Julia E. Bergner, Viktoriya Ozornova, Martina Rovelli, and Claudia Scheimbauer). Ann. K-Theory 6, no. 1, 97-136, 2021.
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A multiplicative comparison of Waldhausen and Segal K-theory
(with Anna Marie Bohmann). Math. Z. 295, no. 3-4, 1205-1243, 2020.
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2-Segal objects and the Waldhausen construction
(with Julia E. Bergner, Viktoriya Ozornova, Martina Rovelli, and Claudia Scheimbauer). Algebr. Geom. Topol. 21, no. 3, 1267-1326, 2021.
PDF
Symmetric monoidal G-categories and their strictification
(with Bert Guillou, J. Peter May and Mona Merling). Q. J. Math. 71, no. 1, 207-246, 2020.
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The edgewise subdivision criterion for 2-Segal objects
(with Julia E. Bergner, Viktoriya Ozornova, Martina Rovelli, and Claudia Scheimbauer). Proc. Amer. Math. Soc. 148, no. 1, 71-82, 2020.
PDF
The 2-dimensional stable homotopy hypothesis
(with Nick Gurski and Niles Johnson). J. Pure Appl. Algebra 223(10):4348-4383, 2019.
PDF
A symmetric monoidal and equivariant Segal infinite loop space machine
(with Bert Guillou, J. Peter May and Mona Merling). J. Pure Appl. Algebra 223(6):2425-2454, 2019.
PDF
2-Segal sets and the Waldhausen construction
(with Julia E. Bergner, Viktoriya Ozornova, Martina Rovelli, and Claudia Scheimbauer). Topology Appl. 235, 445-484, 2018.
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Stable Postnikov data of Picard 2-categories
(with Nick Gurski, Niles Johnson and Marc Stephan). Algebr. Geom. Topol. no. 5, 2763-2806, 2017.
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Extending homotopy theories across adjunctions
(with Nick Gurski and Niles Johnson). Homology Homotopy Appl. 19 no. 2, 89-110, 2017.
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K-theory for 2-categories
(with Nick Gurski and Niles Johnson). Adv. Math. 322: 378-472, 2017.
PDF
Constructing equivariant spectra via categorical Mackey functors
(with Anna Marie Bohmann). Algebr. Geom. Topol. 15(1):537-563, 2015.
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A model structure on GCat
(with Anna Marie Bohmann, Kristen Mazur, Viktoriya Ozornova, Kate Ponto and Carolyn Yarnall). Women in Topology: Collaborations in Homotopy Theory, Contemp. Math. 641, 123-134, 2015.
PDF
Infinite loop spaces, and coherence for symmetric monoidal bicategories
(with Nick Gurski). Adv. Math. 246:1-32, 2013.
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Modeling stable one-types
(with Niles Johnson). Theory Appl. Categ. 26:520-537, 2012.
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Spectra associated to symmetric monoidal bicategories.
Algebr. Geom. Topol. 12(1):307-342, 2012.
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Explicit formulas for 2-characters.
Topology Appl., 157(2):369-377, 2010.
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Other publications:

Homotopical Combonatorics
(joint with Andrew Blumberg, Mike Hill, Kyle Ormsby, and Constanze Roitzheim.) Notices of the AMS, Vol 71, No 2, 2024.
PDF
Topological Invariants of Higher Categories
(joint with Nick Gurski and Niles Johnson.) Notices of the AMS, Vol 66, No 8, 2019.
PDF
Invitación a la teoría de homotopía: Grupo fundamental y espacios recubridores (Introduction to basic concepts in homotopy theory - in Spanish).
Lect. Mat. 39(1):29-48, 2018.
PDF
Espacios de lazos infinitos (Survey paper about infinite loop spaces - in Spanish).
Bol. Mat. 18(2):163-182, 2011.
PDF

Talks

2-categorical constructions and the equivariant Barratt-Priddy-Quillen theorem, Chromatic Homotopy, K-theory and functors, CIRM, January 2023.

2-categorical opfibrations, Quillen's Theorem B, and S^-1S, Higher Homotopical Structures Opening Workshop, CRM, February 2021.

Transfer Systems and Weak Factorization Systems, Online Algebraic Topology Seminar, October 2020.

Operads, ¿cómo parametrizar operaciones de manera coherente?, Cibercoloquio de Matemáticas, October 2020.

Equivariant infinite loop space machines, IHES Summer School, July 2020.

Constructing equivariant spectra via categorical Mackey functors, Banff Research Station, February 2016.

Modeling stable 2-types, MSRI, April 2014.

Graduate students

Diego Manco

Collaborators

Valentina Zapata Castro

Conference organizing

I am co-organizing a Mathematical Research Community (MRC) on Homotopical Combinatorics, in July 2024.

I co-organized the fourth edition of the Women in Topology Workshop, at the Hausdorff Institute in Bonn, Germany, August 2023.

I co-organized the third edition of the Women in Topology Workshop, at the Hausdorff Institute in Bonn, Germany, August 2019.

I co-organized the 62nd Cascade Topology Seminar at PSU, May 11-12, 2019.

I am the administrator for the mailing list of the Cascade Topology Seminar. If you would like to be added to the list, please send me an email with your request.

Reed College hosted the Underrepresented Students in Topology and Algebra Research Symposium (USTARS) in April, 2018.

I co-organized the conference Homotopy Theory in the Ecliptic: Chromatic, Equivariant, and Motivic Mathematics, on the occasion of Doug Ravenel's 70th birthday. The conference took place at Reed College, August 18-21, 2017.

I was the chair of the scientific committee for the Topology Ecuador 2017 Conference that took place in the Galápagos Islands, Ecuador, in August 14-18, 2017.

Kyle Ormsby and I organized the conference on Equivariant and Motivic Homotopy Theory at Reed College, May 30-31, 2015.

Some links:

CV
Reed College Mathematics and Statistics Department
UofC Math Department
MIT Math Department