Ashutosh Kumar: Around a question of Juhasz

Students Set Theory Seminar (HUJI)

We shall meet Wednesday (November 26) in the Hebrew University (in Ross 63), 15:30–17:00.

Speaker: Ashutosh Kumar

Title: Around a question of Juhasz

Abstract: We’ll investigate some results related to a question of Juhasz. We’ll show that consistently, there is no real valued measurable cardinal below the continuum and there is a finitely additive extension of Lebesgue measure whose null ideal is a sigma ideal. We also show that there is a countable partition of
reals into interior free sets under the density topology of any such extension. Joint work with Kunen.

Omer Ben-Neria: Adding clubs with finite conditions to a large cardinal

Friday Set Theory Seminar (HUJI)

We shall meet Friday (November 28) in the Hebrew University math
department building, at 10 am.

Speaker: Omer Ben-Neria (TAU)

Title: Adding clubs with finite conditions to a large cardinal

Abstract: We will describe various methods for adding a club set to
a large cardinal using finite conditions.

 

See you there!

Takayuki Kihara: Recursion theoretic methods in topological dimension theory

Invitation to the Logic Seminar at the National University of Singapore

Date: Wednesday, 26 November 2014, 17:30 hrs

Room: S17#04-05, Department of Mathematics, NUS

Speaker: Takayuki Kihara

Title: Recursion theoretic methods in topological dimension theory

URL: http://www.comp.nus.edu.sg/~fstephan/logicseminar.html

Abstract:
By introducing the notion of generalized Turing degrees in any
admissibly represented space (represented second-countable T0-quotient
space), we provide a refinement of Roman Pol’s solution to Pavel
Alexandrov’s old problem in infinite dimensional topology. Formally,
we show that there is an embedding of an uncountable partial ordering
into the sigma-embeddability ordering of weakly infinite dimensional
metrizable compacta (indeed, metrizable C-compacta, also known as
selectively screenable compacta Sc(O,O) in set theoretic topology).
This is a joint work with Arno Pauly (Univ. Cambridge, UK).

Wojciech Stadnicki: CPA in Mathias model

Tuesday, November 25, 2014, 17:15
Wrocław University of Technology, 215 D-1

Speaker: Wojciech Stadnicki

Title: CPA in Mathias model

Abstract:

We will formulate CPA for Mathias model. We will give its consequences and generalizations.

Miodrag Sokic: Functional classes

Place: Fields Institute, Room 210

Date: 21-11-2014

Time: 13:30-15:00

Speaker: Miodrag Sokic

Title: Functional classes
Abstract: We consider the class of finite structures with functional symbols with respect to the Ramsey property.

Postdoctoral position in set theory (Singapore)

There is a one-year postdoctoral position in set theory available at the National University of Singapore. The expected starting date is April 1, 2015. The job advertisement is given below. To apply for it please email your CV to Dilip Raghavan at raghavan at math dot nus dot edu dot sg. If further application materials such as a reference letter are needed, then you will be contacted directly.

1.       Job title:     Research Assistant

2.       Job Description: This is a one-year postdoctoral position in set
theory.  The NUS logic group consists of 4 faculty members and a
varying numbers of postdoctoral fellows working in set theory and
recursion theory. The research in set theory focuses on Cardinal
invariants of the continuum, iterated forcing, forcing axioms,
partition calculus, and other combinatorial set theory.

3.       Job requirements: The candidate will be expected to contribute to
the research activities of the NUS logic group. There is no formal
teaching requirement.

4.       Closing date: until the position is filled.

5.       Skills: The candidate should have done original work in an area
related to the research interests of the NUS logic group.

6.      Qualifications: PhD in a related field.

Maciej Malicki: Groups of isometries of Polish ultrametric spaces

Saturday, October 18, 2014, 17:15
Wrocław University of Technology, 215 D-1

Speaker: Maciej Malicki (Warsaw School of Economics)

Title: Groups of isometries of Polish ultrametric spaces

Abstract:

We will characterize Polish ultrametric spaces whose isometry groups have a neighborhood basis at the identity consisting of open subgroups with ample generics. We will also define Polish ultrametric W-spaces and give a characterization of W-spaces whose isometry groups have uncountable strong cofinality.

Petr Simon: On a result of F. Rothberger

Wednesday, November 19, 2014, 11:00
Prague – CTS

Speaker: Petr Simon (Charles University in Prague)

Title: On a result of F. Rothberger

Rick Statman: An introduction to λ-calculus

Time:     12:30 – 13:30

Room:     Wean Hall 8220

Speaker:         Rick Statman
Department of Mathematics
CMU

Title:     An introduction to λ-calculus

Abstract:

λ-calculus is that branch of logic which employs algebraic methods to study computer programs and the resulting computable functions. Conventional algebraic structures such as groups and fields are normally absent, and unconventional structures such as Cartesian monoids and near-rings take their place. The object is to classify computer programs and the functions they compute by their functional/algebraic properties such as typeability;

f: D -> R

and invariance;

P(f) = f.

The first lecture will give an introduction to λ-calculus à la Rocquencourt. The basic theorems of reduction and conversion will be discussed,including η-conversion,and the Schönfinkel-Curry theory of combinators will be introduced. The second lecture will describe several algebraic structures, including Cartesian monoids and near-rings, which occur in λ-calculus.

Dan Teng: Semiautomatic Structures

Invitation to the Logic Seminar at the National University of Singapore

Date: Wednesday, 19 November 2014, 17:00 hrs

Room: S17#04-04, Department of Mathematics, NUS

Speaker: Dan Teng

Title: Semiautomatic Structures

URL: http://www.comp.nus.edu.sg/~fstephan/logicseminar.html

Semiautomatic structures generalise automatic structures in the sense
that for some of the relations and functions in the structure one only
requires the derived relations and structures are automatic when all
but one input are filled with constants. One can also permit that this
applies to equality in the structure so that only the sets of
representatives equal to a given element of the structure are regular
while equality itself is not an automatic relation on the domain of
representatives. It is shown that one can find semiautomatic
representations for the field of rationals and also for finite
algebraic field extensions of it. Furthermore, it is shown that there
are semiautomatic ordered rings consisting of the integers augmented
by the multiples of the square-root of a non-square integer; here the
order is the same as the corresponding order on the real numbers.