K-theoretic duality for shifts of finite type

C*-algebras generalizing Cuntz-Krieger algebras can be associated to hyperbolic homeomorphisms of compact metric spaces. They satisfy a non-commutative form of Spanier-Whitehead duality with respect to K-theory. We prove this for the case of subshifts of finite type. The special feature of the present situation is that the constructions are all done on the full Fock space and are very explicit, while the general theorem requires much more abstract machinery.Comment: 23 pages, Latex fil

Bowen Measure From Heteroclinic Points

We present a new construction of the entropy-maximizing, invariant probability measure on a Smale space (the Bowen measure). Our construction is based on points that are unstably equivalent to one given point, and stably equivalent to another: heteroclinic points. The spirit of the construction is similar to Bowen's construction from periodic points, though the techniques are very different. We also prove results about the growth rate of certain sets of heteroclinic points, and about the stable and unstable components of the Bowen measure. The approach we take is to prove results through direct computation for the case of a Shift of Finite type, and then use resolving factor maps to extend the results to more general Smale spaces

Infinity

Prose by Eric Baugh. Finalist in the 2018 Manuscripts Prose Contest

Sexual Orientation Differences in the Association between Physical Activity and Allostatic Load: Results from the National Health And Nutrition Examination Study

Higher levels of allostatic load (AL), a composite measure of the impact of chronic stress on the body, are found among socially marginalized groups compared to privileged groups. AL is associated with premature aging and death, as well as a variety of chronic health conditions that impact quality of life. Effects of AL may be offset by physical activity (PA). Queer populations (including those who identify as lesbian, gay, or bisexual) may be at risk for elevated AL due to repeated exposure to discrimination in the form of sexual minority stress. There is mixed literature on sexual orientation differences in PA and research on AL among queer populations is limited. This study describes sexual orientation differences in the 1) prevalence of PA and mean AL levels and 2) association between PA and AL. Data from the 2001-2015 National Health and Nutrition Examination Survey were used to fit sex-stratified linear regression models assessing sexual orientation (heterosexual, gay/lesbian, bisexual, and heterosexual with same-sex experience) differences as well as sexual orientation-specific associations in PA and AL. AL was assessed using 8 biomarkers, while PA was assessed using metabolic equivalent of task (MET)-hours/week calculated from the Global Physical Activity Questionnaire. Models were adjusted for race/ethnicity, income, education, relationship status, veteran status, and citizenship status. Overall, heterosexual adults reported more PA than their same-sex queer counterparts. Gay men had lower (0.8), while bisexual men had higher AL scores (1.9) than heterosexual men (1.2). Among women, AL score was similar across sexual orientation groups. Overall, more PA was associated with lower AL scores among men and women (badjusted = -0.00508, padjusted=-0.00505, punadjusted =-0.00934, punadjusted =-0.03269, p=0.04), and heterosexual women with same-sex experience (bunadjusted =-0.01059, p=0.02). After adjusting for covariates the association was no longer statistically significant. Consistent with previous work, PA was inversely associated with AL score. PA may be an important modifiable behavior to mitigate some sexual orientation disparities in health

On embedding of the Bratteli diagram into a surface

We study C*-algebras O_{\lambda} which arise in dynamics of the interval exchange transformations and measured foliations on compact surfaces. Using Koebe-Morse coding of geodesic lines, we establish a bijection between Bratteli diagrams of such algebras and measured foliations. This approach allows us to apply K-theory of operator algebras to prove strict ergodicity criterion and Keane's conjecture for the interval exchange transformations.Comment: final versio