Eventss

2019 Dec 23

Combinatorics: Yinon Spinka (UBC)

10:00am to 12:00pm

Location: 

C-400, CS building



Speaker: Yinon Spinka (UBC)


Title: Random graphs on the circle

Abstract: It has long been known that two independent copies of the infinite Erdos-Renyi graph G(\infty,p) are almost surely isomorphic. The resulting graph is called the Rado graph. If the vertices are in a metric space and only nearby vertices may be connected, a similar result may or may not hold, depending on fine details of the underlying metric space. We present new results in the case where the metric space is a circle.
2019 Dec 26

Basic Notions: Menachem Magidor (HUJI) "Regularity properties of subsets of the real line and other polish spaces"

4:00pm to 5:15pm

Location: 

Ross 70
Using the axiom of choice one can construct set of reals which are
pathological in some sense. Similar constructions can be produce such
"pathological" subsets of any non trivial Polish space (= a complete
separable metric space).
A "pathological set" can be a non measurable set , a set which does
not have the property of Baire (namely it is not a Borel set modulo a
rst category set).
A subset of the innite subsets of natural numbers,
can be considered to be "pathological" if it is a counter example to
2020 Jan 09

Basic Notions: Menachem Magidor (HUJI) "Regularity properties of subsets of the real line and other polish spaces"

4:00pm to 5:15pm

Location: 

Ross 70
Using the axiom of choice one can construct set of reals which are
pathological in some sense. Similar constructions can be produce such
"pathological" subsets of any non trivial Polish space (= a complete
separable metric space).
A "pathological set" can be a non measurable set , a set which does
not have the property of Baire (namely it is not a Borel set modulo a
rst category set).
A subset of the innite subsets of natural numbers,
can be considered to be "pathological" if it is a counter example to
2019 Dec 11

Logic Seminar - Eliana Bariga

11:00am to 1:00pm

Location: 

Ross building - Room 63
Eliana Bariga will speak about Definably compact semialgebraic groups over real closed fields.

Abstract: 
Semialgebraic groups over a real closed field can be seen as a generalization of the semialgebraic groups over the real field, and also as a particular case of the groups definable in an o-minimal structure.
2020 Jan 16

Lev Glebsky (UASLP): Residually finite by residually finite extensions are weakly sofic

12:00pm to 1:00pm

Location: 

Manchester Building, Room 209
January 16, 12:00-13:00, Seminar room 209, Manchester building.

Abstract: I plan to show a proof of the statement  "residually-finite-by-residually-finite extensions are weakly sofic". The proof is based on characterization of weakly sofic groups 
by solvability of equations over groups. It looks different from other proofs of soficity and weak soficity. I plan to discuss relations of equations on and over groups with soficity in some details.

2019 Dec 03

Logic Seminar - Antongiulio Fornasiero

1:00pm to 3:00pm

Location: 

Shprintsak building - Room 29
OAntongiulio Fornasiero will speak about definable and interpretable groups and fields in the p-adics.  


Abstract: 
A. Pillay showed that every definable group in the p-adics has a canonical topology and differential structure, and deduced that every definable field is either finite or a finite extension of Q_p.
In a joint work with J. de la Nuez Gonzalez we extend the analysis to interpretable fields, and show that they are either countable or finite extensions of Q_p.
2020 Jan 15

Eshnav: Emmanuel Farjoun - The Geometry of Time according to Einstein

6:00pm to 7:00pm

פרופ' עמנואל פרג'ון: הגאומטריה של הזמן - לפי איינשטיין וחבריו
 
 
לפני כ-100 שנה נצפתה סטיה קלה של אורות כוכבים ממסלולם בעוברם ליד השמש. הסטיה התאימה בקירוב לגישתו הגאומטרית של איינשטיין להבנת הזמן וכח הכבידה, הגרוויטציה הניוטונית. ענף רחב ידים של המתמטיקה, הגאומטריה של רימן, גאוס, לוי-צ'יביטה ורבים אחרים קיבל תנופה רבה כבסיס מתמטי לגאומטריה של המרחב-זמן שפותחה ע"י איינשטיין.
2019 Dec 18

Eshnav: Yuval Nov - Notes, Numbers, Tunes and Tunings

6:00pm to 7:00pm


ד"ר יובל נוב: צלילים, מספרים, מנגינות וכיוונים - מפיתגורס עד ימינו

צלילים ומנגינות הם תופעות המקיימות חוקיות מתמטית.  ההרצאה תציג את החוקיות הזו, ובעיקר תעסוק ב"בעיית הכיוון" של כלי נגינה, ובפתרונות המתמטיים שהוצעו לה במהלך הדורות.  ההרצאה מלווה בדוגמאות רבות, ואינה דורשת ידע מוקדם במוזיקה.
2019 Dec 30

NT Seminar - Shai Evra

2:30pm to 3:30pm

Location: 

Ross 70

Title: Ramanujan Conjectures, Density Hypotheses and Applications for Arithmetic Groups.
Abstract: The Generalized Ramanujan Conjecture (GRC) for GL(n) is a central open problem in modern number theory. Its resolution is known to yield applications in many fields, such as: Diophantine approximation and arithmetic groups. For instance, Deligne's proof of the Ramanujan-Petersson conjecture for GL(2) was a key ingredient in the work of Lubotzky, Phillips and Sarnak on Ramanujan graphs.

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