|
Calendar of Physics Talks Vienna
| CoQuS Colloquium Seminar Talk by Thibaut Sylvestre |
| Speaker: | Thibaut Sylvestre (CoQuS) |
| Abstract: | Surface Brillouin scattering in optical microfibers
Brillouin light scattering in optical fibres is a fundamental interaction between light and sound with important implications ranging from optical sensors to slow and fast light. In conventional optical fibres, light both excites and feels shear and longitudinal bulk elastic waves, giving rise to forward-guided acoustic wave Brillouin scattering and backward-stimulated Brillouin scattering. Here we demonstrate a new type of Brillouin scattering from surface acoustic waves in both tapered and photonic crystal microfibers. This effect may prove interesting for applications to optical sensing that can exploit surface acoustic waves, or for precise metrology of optical micro and nanofibers. |
| Date: | Mon, 03.04.2017 |
| Time: | 17:00 |
| Duration: | 90 min |
| Location: | Atominstitut, Stadionallee 2, 1020 Vienna |
| Contact: | CoQuS Team |
| Covariant Quantum Spaces, Matrix Models and Gravity |
| Speaker: | Harold Steinacker (Univ. Wien) |
| Abstract: | I will discuss geometrical properties and physical perspectives of 4-dimensional covariant quantum spaces, focusing on the fuzzy 4-sphere. These spaces realize quantum geometries with local and global symmetries. The fluctuations on such
a background within the IKKT matrix model lead to a higher spin theory, due to
the underlying twisted bundle structure. Some aspects of the gravitational sector
are elaborated, and the linearized Einstein equations modified by an IR cutoff are extracted under some assumptions.
|
| Date: | Tue, 04.04.2017 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | S. Fredenhagen, H. Steinacker |
| Investigation of noise barrier sound reflection properties |
| Speaker: | Paul Reiter MSc (AIT Austrian Institute of Technology & TU Wien, IAP) |
| Abstract: | Traffic noise from roads and railways is not only a daily annoyance for many people, it can also cause severe health problems. Therefore, noise protection is an important task of modern mobility infrastructure. One of the main measures against traffic noise are noise barriers, which are subject to several measurement standards for their evaluation. These measurement standards allow the investigation of relevant parameters, such as sound transmission, sound reflection and sound diffraction over the top edge of a noise barrier. In recent years, in-situ measurement methods have been developed that can be applied directly on the assembled barrier.
This presentation gives an overview on noise barrier design and functionality. Porous absorbers are introduced as novel components of noise barriers. With regard to noise barrier modelling, the way from a simple plane wave acoustic model to a comp |
| Date: | Tue, 04.04.2017 |
| Time: | 16:00 |
| Location: | Technische Universität Wien, Institut für Angewandte Physik, E134 yellow tower „B“, 5th floor, Sem.R. DB gelb 05 B (room number DB05L03), 1040 Wien, Wiedner Hauptstraße 8-10 |
| Contact: | Ao.Univ.Prof. Dr. Martin Gröschl |
| The MSR Mass and the ℴ(ΛQCD) Renormalon Sum Rule |
| Speaker: | Christopher Lepenik (Univ. Wien) |
| Abstract: | im Rahmen des Teilchenphysik-Seminars |
| Date: | Tue, 04.04.2017 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Hoang, H. Neufeld |
| Log Calabi--Yau compactifications of Landau--Ginzburg models |
| Speaker: | Dr. Victor Przyjalkowski (Steklov Institute, Moscow) |
| Date: | Thu, 06.04.2017 |
| Time: | 11:00 |
| Duration: | 60 min |
| Location: | ESI, Boltzmann Lecture Hall |
| Contact: | secr@esi.ac.at |
| Speaker: | Juan Valiente-Kroon (Queen Mary) |
| Abstract: | In this talk I will give an overview of Friedrich’s construction of a regular asymptotic initial value problem at spatial infinity and the open questions related to it. In particular, I will show how this framework can be used to identify initial data sets for the vacuum Einstein field equations which should lead to spacetimes not satisfying the peeling behaviour. This is research in collaboration with Edgar Gasperin. |
| Date: | Thu, 06.04.2017 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien |
| Contact: | P.T. Chrusciel |
| Universal corrections to entanglement entropy of local quantum quenches and scrambling time |
| Speaker: | Surbhi Khetrapal (Centre for High Energy Physics, Indian Institute of Science) |
| Abstract: | We study the time evolution of single interval Renyi and entanglement entropies following local quantum quenches in 2d CFTs at finite temperature for which the locally excited states have a finite temporal width, epsilon. We show that, for local quenches produced by the action of a conformal primary field, the time dependence of Renyi and entanglement entropies at order epsilon^2 is universal. It is determined by the expectation value of the stress tensor in the replica geometry and proportional to the conformal dimension of the primary field generating the local excitation. We also show that in CFTs with a gravity dual, the epsilon^2 correction to the holographic entanglement entropy following a local quench precisely agrees with the CFT prediction. We compute another correction when the CFT has higher spin chemical potential, and find that its time dependence is universal.
...
|
| Date: | Thu, 06.04.2017 |
| Time: | 16:00 |
| Duration: | 60 min |
| Location: | SEM 136, TU Wien, Freihaus, 10th floor (Wiedner Hauptstr. 8-10, A-1040 Vienna) |
| Contact: | Daniel Grumiller and Johanna Knapp |
| Speaker: | Jorge Alegre Cebollada (National Center for Cardiovascular Research Madrid, Spain) |
| Abstract: | The
heart
is
a
mechanical
machine
that
has
little
room
for
failure.
Differently
to
pumps
manufactured
by
men,
the
heart
is
built
upon
soft
tissue.
What
are
the
mechanical
properties
of
cardiac
tissue
and
its
constituent
proteins
sustaining
the
remarkable
activity
of
the
heart?
How
is
the
elasticity
of
the
myocardium
tuned
to
accommodate
the
expansion
of
the
ventricles
during
diastole?
How
do
mutations
in
proteins
with
a
mechanical
role
trigger
the
development
of
life-‐threatening
cardiomyopathies?
Since
the
mechanical
properties
of
proteins
are
not
accessible
to
standard
bulk
biochemical
techniques,
our
lab
takes
a
multidisciplinary
approach
to
try
to
answer
all
these
questions.
We
specialize
in
single
molecule
methods
using
atomic
force
microscopy
(AFM),
which
are
able
to
measure
the
effects
of
mechanical
forces
on
proteins.
We
focus
on
titin
and
cardiac
myosin
binding
protein
C,
two
k |
| Date: | Fri, 07.04.2017 |
| Time: | 10:00 |
| Location: | Seminarraum Lehar 02, Lehartrakt BC, 2nd floor TU Wien, Getreidemarkt 9, 1060 Vienna |
| Contact: | Univ.Prof. Dr. G. Schütz |
|