# Seminar on Free Probability and Random Matrices Winter 2019

## Organizer: J. Mingo <!-- // // format date as dd-mmm-yy // example: 12-Jan-99 // function date_ddmmmyy(date) { var d = date.getDate(); var m = date.getMonth() + 1; var y = date.getYear(); // handle different year values // returned by IE and NS in // the year 2000. if(y >= 2000) { y -= 2000; } if(y >= 100) { y -= 100; } // could use splitString() here // but the following method is // more compatible var mmm = ( 1==m)?'Jan':( 2==m)?'Feb':(3==m)?'Mar': ( 4==m)?'Apr':( 5==m)?'May':(6==m)?'Jun': ( 7==m)?'Jul':( 8==m)?'Aug':(9==m)?'Sep': (10==m)?'Oct':(11==m)?'Nov':'Dec'; return "" + (d<10?"0"+d:d) + "-" + mmm + "-" + (y<10?"0"+y:y); } // // get last modified date of the // current document. // function date_lastmodified() { var lmd = document.lastModified; var s = "Unknown"; var d1; // check if we have a valid date // before proceeding if(0 != (d1=Date.parse(lmd))) { s = "" + date_ddmmmyy(new Date(d1)); } return s; } // // finally display the last modified date // as DD-MMM-YY // document.write( "Last modified on " + date_lastmodified() ); // -->

Thursday, May 30, 3:30 - 5:00, Jeff 115
Daniel Muñoz George (Queen's)
Graph Sums
In this talk we are interested in finding an optimal upper bound for sums of product of matrices entries with some restrictions. These kinds of sums appear canonically in many problems such as the trace of the product of matrices. In order to find this upper bound we will associate a graph to every sum. This translate the problem to finding an upper bound to some operator associated to a graph. We will use some traffic and functional analysis techniques to solve our problem.
Wednesday, May 8, 3:30 - 5:00, Jeff 319
Sang-Gyun Youn (Queen's)
Capacities of quantum channels and $SU(2)$-covariant channels
Classical/quantum capacity of quantum channels will be discussed in the first half. Then I will introduce a class of channels that can preserve SU(2)-symmetries.
Tuesday, May 7, 3:30 - 5:00, Jeff 319
Pei-Lun Tseng (Queen's)
Operator-Valued Infinitesimal Free Additive Convolution 2
We covered the most of the background knowledge that we need to construct the operator-valued infinitesimal free convolution (OVIC ) last talk. In this talk, we will define the C^*-operator-valued infinitesimal probability spaces and start to construct the OVIC.
Wednesday, May 1, 3:30 - 5:00, Jeff 319
Sang-Gyun Youn (Queen's)
Minimum output entropy and capacities of quantum channels
In this talk, minimum output entropy (MOE) and Holevo/quantum capacity of quantum channels will be discussed. And I will sketch how the additivity conjecture of MOE was disproved by random unitary channels.
Monday, April 29, 3:30 - 5:00, Jeff 234
Pei-Lun Tseng (Queen's)
Operator-Valued Infinitesimal Free Additive Convolution 1
In this talk, we will recall some basic knowledge of operator-valued probability spaces, and some analytical properties of the operator-valued Cauchy transforms. Then, we will introduce the C^*-operator-valued infinitesimal probability spaces, and the operator-valued infinitesimal Cauchy transform. We will also construct the operator-valued infinitesimal R-transform if time permits.
Wednesday, April 24, 3:30 - 5:00, Jeff 319
Sang-Gyun Youn (Queen's)
A mathematical introduction to quantum information theory
As a cornerstone for discussing quantum information theory, I will explain what quantum states and quantum channels are in this talk. And I will introduce some important properites of quantum channels such as the entanglement-breaking property and classical/quantum capacity.
Monday, April 22, 3:30 - 5:00, Jeff 319
Jamie Mingo (Queen's)
Infinitesimal Freeness and the Gaussian Orthogonal Ensemble, II
I will continue from last week.
Monday, April 8, 3:30 - 5:00, Jeff 422
Pei-Lun Tseng (Queen's)
Operator-valued infinitesimal freeness
In this talk, we will introduce the operator-valued infinitesimal probability space and we will give an characterization of operator-valued infinitesimal freeness.
March 4 - 29
Centre de Recherches Mathématiques (l'Université de Montréal)
In the month of March the seminar will move to the Centre de Recherches Mathématiques at l'Université de Montréal for a one month focus program.
Monday, February 25, 10:00 - 11:30, Jeff 319
Pei-Lun Tseng (Queen's)
Fully Matricial Functions, Part IV
I will discuss § 2.3 Difference-Differential Calculus and § 2.4 Taylor-Taylor Expansion.
Monday, February 11, 10:00 - 11:30, Jeff 319
Jamie Mingo (Queen's)
Fully Matricial Functions, Part III
I will continue the discussion of the difference-differential calculus.
Monday, February 4, 10:00 - 11:30, Jeff 319
Jamie Mingo (Queen's)
Fully Matricial Functions, Part II
I will discuss the difference-differential calculus.
Monday, January 28, 10:00 - 11:30, Jeff 319
Jamie Mingo (Queen's)
Fully Matricial Functions
When one extends the Cauchy transform to the operator valued case one cannot recover the law of the random variable without extending to the matricial case. This requires one to develop the theory of fully matricial functions. These are functions defined on open sets in C*-algebras that extend to matrices of all orders in a regular way. I will present the example of the Cauchy transform and introduce fully matricial functions.
Monday, January 21, 10:00 - 11:30, Jeff 319
Neil MacVicar (Queen's)
Tensor Products of Modules and Vector Spaces
This talk will review the construction of the tensor product of modules and its universal property. This property can be used to establish associativity, commutativity over direct sums, and a check for linear independence when our modules are vector spaces. I also hope to give a brief introduction to tensor norms.

Previous Schedules

Getting to Jeffery Hall from the Hotel Belvedere