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{\Large המחלקה למתמטיקה, בן-גוריון}

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{\Huge לוגיקה, תורת הקבוצות וטופולוגיה}\\[0.2\baselineskip]

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\textbf{ב}\emph{יום שלישי,  5 בינואר, 2016}
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\textbf{בשעה} \emph{12:15 -- 13:40}
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\textbf{ב}\emph{Math -101}

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ההרצאה

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{\Large\bfseries The Lusternik-Schnirelmann category of general metric spaces\par}
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תינתן על-ידי
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{\large\scshape Tulsi Srinivasan 
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  (Ben-Gurion University of the Negev)
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\textbf{תקציר:}
  The Lusternik-Schnirelmann category (LS-category) is a topological invariant that has historically been studied for absolute neighbourhood retracts. I will discuss how the theory of the LS-category can be extended to general metric spaces. One can obtain upper bounds for the LS-category of general spaces by using dimension-theoretic techniques to prove analogues to the Grossman-Whitehead theorem and Dranishnikov`s theorem. One can also obtain lower bounds in terms of cup-length, category weight and Bockstein maps. These results can be used to calculate the LS-category for some compacta like the Menger spaces and Pontryagin surfaces. I will also compare this definition with Borsuk`s shape theoretic LS-category. Finally, I will talk about potential applications of this work to geometric group theory, specifically the possibility of obtaining an analogue to the Bestvina-Mess formula in terms of LS-category.
  


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