Strongly coupled theories exhibiting walking dynamics provide a scenario for beyond the Standard Model physics, in which electro-weak symmetry is broken dynamically and the large hierarchy between the electro-weak and Planck energy scales is naturally generated. In this talk, we discuss the construction of walking theories within the context of gauge-gravity duality, focusing in particular on the circumstances under which a parametrically light composite state, the dilaton, is present in the spectrum. The examples we provide come both from bottom-up models as well as top-down models embedded in M-theory and type-IIB supergravity, and include the baryonic branch of the Klebanov-Strassler field theory.

Si l'on force des particules discrètes à s'écouler dans un canal étroit ou à travers une constriction, des effets assez surprenants peuvent se produire. J'aborderai quelques exemples de tels écoulements.
Dans le domaine de la microfluidique, la mise au point de laboratoires sur puce demande de transporter des émulsions très concentrées à travers des microconduits. Or, expérimentalement, cet écoulement confiné peut fortement s'écarter des prévisions faites sur la base de la rhéologie macroscopique de ces matériaux [1]. De semblables écarts ont été relevés pour d'autres types de solides mous, comme les pâtes colloïdales. Les modèles élasto-plastiques que nous avons développés clarifient l'origine de ces déviations sous confinement. En effet, ces modèles génériques, qui décrivent un ensemble de régions mésoscopiques alternant entre un comportement élastique et une phase de relaxation plastique, nous ont aidés à faire la part des choses entre la contribution du chargement hétérogène et la rhéologie spécifique près des parois [2].
Pour en venir à des situations d'écoulement non uniforme, je parlerai ensuite d'écoulements à travers une constriction étroite, pour lesquels des bouchons peuvent se produire et interrompre le débit. Pour des écoulements granulaires, ces bouchons peuvent être détruits à l'aide de vibrations, mais ils ne cèdent pas spontanément : ils ont des temps de vie très largement distribués. Je présenterai un modèle simple qui rend compte de ces statistiques anormales. D'un autre côté, quand les particules sont des piétons franchissant une porte, les bouchons sont résolus naturellement. Néanmoins, des similitudes avec leurs homologues granulaires existent. [4-5].

[1] Goyon, J., et al. "Spatial cooperativity in soft glassy flows." Nature 454.7200 (2008).
[2] Nicolas, Alexandre, and Jean-Louis Barrat. "Spatial cooperativity in microchannel flows of soft jammed materials: A mesoscopic approach." Physical review letters 110.13 (2013).
[3] Nicolas, Alexandre, Garcimartín, Ángel and Zuriguel, Iker, "A trap model for clogging and unclogging in granular hopper flows". Submitted (2017)
[4] Zuriguel, Iker, et al. "Clogging transition of many-particle systems flowing through bottlenecks." Scientific reports 4 (2014): 732
[5] Nicolas, Alexandre, Sebastián Bouzat, and Marcelo N. Kuperman. "Pedestrian flows through a narrow doorway: Effect of individual behaviours on the global flow and microscopic dynamics." Transportation Research Part B: Methodological 99 (2017).

Interfaces of theoretical physics with other fields vary along two axes: whether exhaustive microscopic knowledge is available to construct models, and whether physics provides substance or only tools. I will argue that even interfaces that are remote on both counts, e.g. with economics, ecology and evolution, can open important new questions in our field, while answering these questions is likely to happen at more controlled interfaces, e.g. with cell biology.

From kinetic theories of economic interactions to spin glass phases in ecological dynamics, I will discuss some examples in my experience that either resonated or not with scientists in other fields, and sometimes pushed our tools in unexpected directions, to ask when physics can have a meaningful two-way interaction with these other theoretical corpora.
I will in particular propose that statistical physics can give a sharp meaning to the notion of biological function, which other sciences have largely failed to theorize. In turn, this notion poses definite mathematical and empirical questions in systems such as transport and metabolic networks, which can provide a testing ground for theoretical ideas across interfaces.

In general, single-walled carbon nanotubes (SWCNTs) are synthesized by
chemical vapor deposition (CVD) at 700-900ºC using Fe, Co and Ni catalysts. However,
due to Ostwald ripening of catalyst particles, the uniformity of the SWCNT diameter is
not sufficient, which is not preferable for electronics applications. In addition, reduction
of the growth temperature is desired for realization of SWCNT devices compatible with
LSI manufacturing processes. In this study, we performed SWCNT growth by alcohol
catalytic CVD using platinum-group metal catalysts (Ru, Rh and Pt), since these metals
have high-melting points (> 1700ºC), and reduction of Ostwald ripening is expected. By
optimizing the growth condition, SWCNTs were grown from these catalysts at the growth
temperature between 500 and 700ºC. Irrespective of the catalyst metals, the diameter and
chirality distribution became narrower, as the growth temperature decreased. In particular,
the diameters of most SWCNTs grown from Pt catalysts were below 1 nm and their
diameter distribution was quite narrow [1]. On the other hand, SWCNTs were grown from
Rh catalysts even at 300ºC, which is the lowest temperature record of SWCNT growth
[2]. We will also discuss growth mechanism of SWCNTs from these platinum-group
metal catalysts.
[1] T. Maruyama et al. Carbon 96 (2016) 6.
[2] T. Maruyama et al. Carbon 116 (2017) 128.

Recent studies have shown that the presence of boundaries can strongly affect the dynamics of physical systems.
For example, negative mobility and fluid recirculation occurs when an electrolyte is driven in a varying-section channels, rectification occurs active particles such as molecular motors or active swimmers moving in inhomogeneous environments and off--diagonal terms in the mobility tensor appears for binary mixtures of hard sphere confined between corrugated plates.
Clearly the interplay between the confined systems and the confining walls is maximized when the typical length scales of the confined system match with the size of the confining walls.
In this contribution I will discuss the general mechanisms at the basis of the interplay between the confined system and the confinement. In particular, by means of a few example I will show how analytical insight into the possible regimes can be attained.

Firstly, I will discuss how the electrostatic interaction between a tracer particle and the channel walls affect particle dynamics. In such a scenario, novel dynamical regimes such as negative mobility and asymmetric passage times can arise due to the interplay between the electrostatic interactions and the local entropic drive induced by the varying--section channel.

Secondly I will show how the insight gained by such studies can be transferred to the problem of polymer translocation across varying--section channels.
In particular, I will show that, under suitable approximation, it is possible to reduce the problem of polymer translocation across varying--section channels to that of a single point--like particle under an effective potential that can be derived from the equilibrium local free energy of the polymer. Interestingly, the model predicts a non-monotonous dependence on the translocation time of the polymer across the pore appears. By comparing with Brownian dynamics simulations I will discuss the quantitative reliability of the point--like approximation as well as its regime of validity.

Finally, when the interactions between the confined systems and the confinement are non-conservative, as it happens for hydrodynamic interactions, the interplay between the confined system, say an active swimmer, and the confinement is more involved. I will, briefly discuss how such a scenario can be described on the basis of the experienced gained with the conservative forces.

While the LHC is still at the beginning of its life cycle, no major increases in the centre-of-mass energy are expected in the future, and the absence of apparent signs of new physics call for the development of precision tests of the Standard Model with the existing and future data.
Vector Boson Scattering (VBS) and di-Higgs production will play a crucial role in this effort, as they give direct access to the very heart of the electroweak symmetry breaking: on the one side by measuring the impact of the Higgs boson in the VBS unitarity, on the other side by investigating the self-coupling of the Higgs boson itself.

In order to develop spintronic devices, a precise control of the magnetic state in ultrathin films is necessary. Starting from the Fe/Ir interface, known to generate a large Dzyaloshinskii-Moriya interaction, we show how to obtain and tune spin spirals or magnetic skyrmions using spin-polarized scanning tunneling microscopy (SP-STM).
Since the lattice mismatch between Fe and Ir is very large, the epitaxially grown double Fe atomic layer on Ir(111) exhibits a network of dislocation lines along high-symmetry directions. These lines allow to relieve the epitaxial strain in the film and fix the propagation direction of spin spirals with a period about 1.5 nm. When atomic hydrogen is incorporated in the double layer film, the dislocation lines network disappears and is replaced by a p(2x2) hexagonal superstructure. The propagation direction of the spin spirals is thus not fixed anymore and their period increases to 3.5 nm. Furthermore, they transform into skyrmions under application of a magnetic field of 3 T whereas, this is not the case in the pristine double layer. Ab initio calculations indicate that the H atoms must be located between the two Fe layers and allow to reproduce the observed results.
Another possibility to modify the magnetic state is to add one more atomic Fe layer. As well as in the double layer film, spin spirals propagate along dislocation lines in the triple layer film. In addition, the spacing between the lines is varying over the sample surface which means that the strain relief is also not uniform. Our measurements revealed a clear correlation between the dislocation line spacing and the magnetic period. Based on a simple micromagnetic model, we attribute this observation to a modulation of the effective exchange coupling by the epitaxial strain relief.
Although the effect of strain relief was studied at low temperature, we also investigated the temperature dependence of the spin spirals. Whereas no spiral could be observed in the double layer above 150 K, the spirals are still stable in the triple layer Fe up to room temperature. Moreover, their period increases drastically and becomes 15 times larger than at 8 K. In order to explain this unexpected temperature-dependent behaviour, we propose a classical spin model based on different magnetic parameters in the three Fe layers. This model allows us to reproduce the period increase using both a mean-field and a Monte Carlo approach.
Under application of a magnetic field, the low-temperature spin spirals split up into skyrmions with a typical size about 5 nm. We demonstrate that they can reliably be written and deleted locally by the STM tip. The strong-bias polarity dependence and the linear behavior of the threshold voltage with the tip-sample distance shows that electric field plays the dominant role in the switching mechanism.

Glass films created by vapor depositing particles onto a properly prepared substrate have properties similar to those of ordinary glasses aged for thousands of years. It has been a challenge to study these glasses using computer simulations due to the long time scales involved. Here we use computer simulations to examine two aspects of vapor deposited glasses. First, we examine the role of surface mobility on the creation of ultra-stable vapor deposited glasses. We show that the surface mobility plays the same role in creating vapor deposited glasses as the bulk mobility does for glasses cooled at a constant rate. Second, we examine the melting of stable glasses. Vapor deposited glasses can melt via a front initiated at the surface, while this melting mechanism is not observed for liquid cooled glasses. We use the swap Monte Carlo algorithm to create stable glasses and examine the conditions where the glasses melt via a front versus a bulk mechanism. We also examine what controls the front velocity.