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## Tuesday 20th March: STP Seminar – “From Hilbert’s 16th Problem to Physics”

**Title: **From Hilbert’s 16th Problem to Physics

**Speaker: **Charles Nash (NUI Maynooth)

**Abstract: **We shall describe a link between Hilbert’s sixteenth problem (part (i)) concerning real algebraic curves and condensed matter physics. The central result is some work of Kenyon and Okounkov (2006). The physics involves so called dimer problems for periodic bipartite and non-bipartite graphs. A differential geometric approach will be introduced to help clarify matters. It transpires that real K-theory underlies the systems studied.

**Time:** Tuesday 20th March 2018, 2.30pm.

**Place: **Lecture Room, School of Theoretical Physics, DIAS, 10 Burlington Road, Dublin 4.

## Tuesday 6th March: STP Seminar – “Quantum Correlations in Space & Time”

**Title: **Quantum Correlations in Space & Time

**Speaker: **Joe Fitzsimons (Singapore University of Technology and Design)

**Abstract: **In ordinary, non-relativistic, quantum physics, time enters only as a parameter and not as an observable: a state of a physical system is specified at a given time and then evolved according to the prescribed dynamics. While the state can, and usually does, extend across all space, it is only defined at one instant of time, in conflict with special relativity where space and time are treated on an equal footing. In this talk, I will examine the consequences of extending the notion of the quantum density matrix to multiple spatial and temporal measurements. To this end, I will introduce the concept of a pseudo-density matrix which treats space and time indiscriminately. This matrix in general fails to be positive for timelike separated measurements, motivating the definition of a measure of causality that discriminates between spacelike and timelike correlations. I will present the results of recent NMR experiments to measure causal correlations and their decay under the effects of noise. In the second half of the talk, I will present an application on the pseudo-density framework to bounding the capacity of quantum channels, and show how it can be used to obtain new bounds for the capacity of shifted depolarizing channels.

**Time:** Tuesday 6th March 2018, 2.30pm.

**Place: **Lecture Room, School of Theoretical Physics, DIAS, 10 Burlington Road, Dublin 4.

## Tuesday 27th February: STP Seminar – “Anomalous Transport”

**Title: **Anomalous Transport

**Speaker: **Karl Landsteiner (Universidad Autónoma de Madrid)

**Abstract: **The concept of symmetry is one cornerstone of modern theoretical physics, quantum mechanics is another. Sometimes they are incompatible with each other. These incompatibilities are called anomalies. They constrain possible fermion spectra of gauge theories and explain otherwise forbidden processes such as the decay of the neutral pion into two photons. In the recent years it has turned that anomalies have also profound impact on transport theory of relativistic matter. Anomalies induce exotic new transport phenomena such as the chiral magnetic and the chiral vortical effects. I will review anomaly induced transport phenomena and some of its applications in the quark gluon plasma and a in new exciting class of materials: the Weyl semimetals.

**Time:** Tuesday 27th March 2018, 2.30pm.

**Place: **Lecture Room, School of Theoretical Physics, DIAS, 10 Burlington Road, Dublin 4.

## Thursday 15th March: STP Seminar – “Einstein Gravity From Conformal Field Theory”

**Title: **Einstein Gravity From Conformal Field Theory

**Speaker: **Andrei Parnachev (TCD)

**Abstract: **We will analyse the Regge limit of certain four point functions in CFTs and will argue that holographic CFTs must be described by the Einstein gravity.

**Time:** Thursday 15th March 2018, 2.30pm.

**Place: **Lecture Room, School of Theoretical Physics, DIAS, 10 Burlington Road, Dublin 4.

## Tuesday 13th February: STP Seminar – “An Introduction to Causal Set Theory”

**Title: **An Introduction to Causal Set Theory

**Speaker: **Dionigi M.T. Benincasa (DIAS)

**Abstract: **Causal set theory is a sum-over-histories approach to quantum gravity, where the histories are discrete spacetimes (called causal sets) defined as locally finite partial orders. Causal sets were proposed independently by ’t Hooft, Myrheim, Finklestein and Sorkin in the 70s and 80s, and have been championed by R. Sorkin ever since.

In this talk I will give a brief introduction to causal set theory, building towards some of the developments of the last decade. These include a definition of the causal set scalar curvature, and therefore of a causal set action analogous to the Einstein-Hilbert action of GR, which can be used to define causal set dynamics; as well as a formulation of quantum field theory on causal sets. If time permits I will discuss some recent (puzzling) results concerning the entanglement entropy of a free scalar field on a causal set.

**Time:** Tuesday 13th February 2018, 2.30pm.

**Place: **Lecture Room, School of Theoretical Physics, DIAS, 10 Burlington Road, Dublin 4.

## Tuesday 6th February: STP Seminar – “A Hopf algebra for Feynman diagrams and integral”

**Title: **A Hopf algebra for Feynman diagrams and integral

**Speaker: **Ruth Britto (Trinity College Dublin)

**Abstract: **I will present a combinatorial operation on one-loop Feynman diagrams, described by cutting and pinching edges, that corresponds to the Hopf-algebraic coaction on the multiple polylogarithms resulting from their integration. A generalization of this operation, expressed simply in terms of master integrands paired with master contours, can be applied directly to larger classes of functions including hypergeometric functions. I will discuss applications to analyses of discontinuities of and differential equations for Feynman diagrams.

**Time:** Tuesday 6th February 2018, 2.30pm.

**Place: **Lecture Room, School of Theoretical Physics, DIAS, 10 Burlington Road, Dublin 4.

## Mon 5 Feb 2018 : 75th Anniversary of Erwin Schrödinger’s ‘What is Life?’ lecture today

Today (05.02.18) marks the 75^{th} anniversary of a lecture in Dublin regarded as one of the most important scientific lectures of all time.

On 5^{th} February 1943, Nobel Prize-winning physicist, Professor Erwin Schrödinger, then Director of Theoretical Physics at the Dublin Institute for Advanced Studies (DIAS), delivered the first of his renowned ‘What is Life?’ lectures. He delivered further lectures in his ‘What is Life?’ series over the following month.

Collectively, the lectures which were hosted by Trinity College Dublin, are credited with transforming our understanding of genetics and inspiring the discovery of DNA.

**Schrödinger in Ireland**

Professor Schrödinger had been brought to Ireland by Éamon de Valera on the eve of World War II. As an outspoken and high-profile critic of the Nazi regime, he had been forced to flee his native Austria.

De Valera, who was Taoiseach at the time, was determined to establish a high-level research institute in Ireland – the Dublin Institute for Advanced Studies – and approached Schrödinger to be the first Director of its School of Theoretical Physics. Schrödinger remained in that post until his retirement in 1955, when he returned to Austria.

Commenting today, Dr. Eucharia Meehan, CEO and Registrar of DIAS, said: “We are immensely proud to have had Professor Erwin Schrödinger as the first Director of DIAS’s School of Theoretical Physics.

“DIAS is home to a rich treasure trove of historical artefacts from Schrödinger’s time in Dublin. Along with lots of fascinating photographs of Schrödinger with Éamon de Valera, we have a letter to Schrödinger from Francis Crick crediting ‘What is Life?’ as an influence in his and James Watson’s discovery of DNA.”

Speaking today, Professor Werner Nahm, Director of the School of Theoretical Physics said: “At the DIAS School of Theoretical Physics, we are very proud to celebrate the 75^{th} anniversary of this hugely influential lecture series, delivered by our first Director.

“Schrödinger’s ‘What is Life?’ lecture series not only brought a broad range of theoretical physics concepts to the non-expert but have also been widely credited with inspiring the discovery and decoding of DNA, our genetic building blocks.”

**‘What is Life?’**

The lectures delivered by Schrödinger 75 years ago dealt with the physical aspects of living cells; specifically, with the bearing of quantum theory on the structure of chromosomes and the nature of mutation. They presented an early theoretical description of the storage of genetic information and have been credited as a source of inspiration in the discovery of DNA and subsequent decoding of the human genome.

The lectures were public lectures addressed to a general audience. The requirement to give such lectures was written by de Valera into the act establishing DIAS.

The ‘What is Life?’ lectures were subsequently published in a book of the same name and translated into German, French, Swedish, Japanese, Italian and Russian.

At the time, the lectures were covered by international outlets such as Time Magazine, as well as Ireland’s national media.

Further information about DIAS and Erwin Schrödinger is available here : https://www.dias.ie/category/stp/stp-history/#Statutory_Public_Lectures.

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**ENDS**

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**Further information, contact: Eva Dowling / Martina Quinn, Alice PR & Events. Tel: 083-1496045 / 087-6522033, email: media@alicepr.com**

**Notes to Editor**

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__Notes to photo editors__

To mark today’s anniversary, DIAS have released a series of photos and newspaper clippings from Erwin Schrödinger’s time at DIAS from their archive. These are available by emailing eva@alicepr.com.

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__About DIAS__

DIAS was founded by Éamon de Valera in 1940 as a centre of excellence for advanced scholarship focused on three disciplines: Celtic Studies, Theoretical Physics and Cosmic Physics. As a globally embedded institution which attracts scholars and academics from around the world, it conducts and publishes advanced research. The organisation also leads Ireland’s participation in a number of international research endeavours, runs the Dunsink Observatory and coordinates a range of national initiatives on behalf of government. Further information is available at www.dias.ie.

Follow DIAS on social media:

- Twitter: @DIAS_Dublin
- Facebook: facebook.com/DIASDublin

## Thurs 25 Jan 2018 – Group Photo of #BalFest80

Attendees at #BalFest80 taking place here at #DIASDublin in the School of Theoretical Physics this week

## Tues 23 Jan 2018 : Ambassador of the Republic of India visits DIAS Dublin

Her Excellency Ambassador Vijay Thakur Singh, Ambassador of the Republic of India to Ireland visited DIAS Dublin today. The “Quantum Physics: Fields, Particles & Information Geometry” conference has been organised by the School of Theoretical Physics, DIAS in honour of Professor A. P. Balachandran (Syracuse University) on the occasion of his 80th birthday and it is taking place this week at DIAS. The Ambassador met with Professor Balachandran, DIAS staff and academics attending the conference.

#BalFest80

## Quantum Physics: Fields, Particles & Information Geometry

**Quantum Physics: Fields, Particles & Information Geometry** is organised by the Dublin Institute for Advanced Studies In honour of A. P. Balachandran on the occasion of his 80th birthday.

It will be held at 10 Burlington Road, Dublin 4 from **Monday**** 22nd until Friday 26th of January 2018**.

View the conference website here.