7 NOV 2019
11:00 - 12:00

Abstract: We use the path integral optimization approach of Caputa, Kundu, Miyaji, Takayanagi and Watan-abe to find the time slice of geometries dual to vacuum, primary and thermal states in the TTde-formed two-dimensional CFTs. The obtained optimized geometries actually capture the entire bulk which fits well with the integrability and expected UV-completeness ofTT-deformed CFTs. When the deformation parameter is positive, these optimized solutions can be reinterpreted as geometries at finite bulk radius, in agreement with a previous proposal by McGough, Mezei, and Verlinde. We also calculate the holographic entanglement entropy and quantum state complexity for these solutions. We show that the complexity of formation for the thermofield double state in the deformed theory is UV finite and it depends on the temperature.


Larak Seminar Room

5 NOV 2019
14:00 - 15:00

Location: Farmanieh Building, Seminar Room Class D (3rd floor)

Address: Next to Kouhe Nour Building, Farmanieh Ave., IPM, Tehran

4 NOV 2019
16:00 - 18:00

Avecinna and God Knowledge of Particulars

4 NOV 2019
11:00 - 12:00

Based on: Arxiv: 1710.04061 [hep-ph]

Abstract: The asymmetry between baryon and anti-baryons in the universe is still a mystery. Among the proposed solutions, Electroweak Baryogenesis (EWBG) is particularly interesting because of its link to electroweak scale, which increases its chance of being tested in experiments. A large number of SM extensions that could lead to successful EWBG have been proposed. In principle, a detailed phenomenological study of each individual model is very time consuming and not feasible . To avoid such a cumbersome exercise it was proposed to test EWBG, or at least a large class of EWBG models, in a single framework based on the Standard Model Effective Field Theory (SM- EFT). In this paper, the authors argue that EWBG cannot be fully studied within the SM-EFT framework. The main reason is that the SM-EFT breaks down in the scalar sector, because new light degrees of freedom are necessary to obtain a strong first-order phase transition. This breakdown is communicated to the CP-violating sector of the theory via the equation of motion of the Higgs field, which is used to construct the basis set of SM-EFT operators. The result is that there is no separation of scales and higher-dimensional operators cannot be neglected, thus invalidating the SM-EFT approach.

Larak Seminar Room

3 NOV 2019
15:00 - 16:00

Abstract:
One central question about the visual system is how objects are represented in high-level visual neurons. We investigated this question on a special class of objects--faces. Combining fMRI and electrophysiology, neurons in macaque face patches were targeted for recording while presenting thousands of facial images generated by an algorithm developed in the field of computer vision. We found that each face cell's firing rate is proportional to the projection of an incoming face stimulus onto a single axis in this space. Using this code, we could decode faces from neural population responses and predict neural firing rates to faces. Further analysis revealed a difference in feature tuning across different patches: while face cells in the middle patches code the overall shape of the face, cells in the most anterior patch AM code intensity variations independent of shape.

Venue:
School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM),
Opposite the ARAJ, Artesh Highway, Tehran, Iran on map




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24 OCT 2019
11:00 - 12:00

Abstract: I will review briefly the historical evolution of black hole physics and holography and their recent developments, then I will focus on their connection with quantum entanglement and quantum information. Finally, I will talk about a recently developed topic: Holographic quantum error correction.


Larak Seminar Room

23 OCT 2019
15:30 - 17:30

We show that Martin's Maximum${}^{++}$ implies Woodin's ${mathbb P}_{ m max}$ axiom ($star$). This is joint work with David Aspero.

23 OCT 2019
14:00 - 15:00

Plastic electronics and its traps

Abstract:

Beside the big advantages of molecular electronic, presence of trapping states in
these materials is considered as one of the big dilemmas in the field. Because these trap states that lie in forbidden band gap that is detriment for current flow, and they waste power. Electron trapping is a well-recognized issue in organic semiconductors, in particular in conjugated polymers, leading to a significant electron mobility reduction in materials with electron affinities smaller than 4 eV. Many researchers are trying to figure out that what is the origin of these traps and how to overcome this issue. Space-charge limited current measurements in diodes indicate that these traps have similar molecular origin, while calculations show that hydrated molecular oxygen is a plausible molecular candidate, with the tail of the solid-state electron affinity distribution reaching values as high as 4 eV. We, recently, proposed a method to dilute and eliminate traps that is based on their statistical distribution in the material. By mixing a conjugated polymers in an insulating polymer matrix, one can dilute trap density and hence eliminate their effect on electron mobility. Trap dilution not only improves transport but also reduces trap-assisted recombination, boosting the efficiency of polymer light emitting diodes. This talk, also will have a short review on 2 recent major works that one proposes a trap free window for conjugated semiconductors and the other proposes a new method on how one can get rid of these traps by dry-annealing the material while it is contradictory with preceding works in some parts