سخنران: دکتر بهرام مشهون (دانشگاه میزوری، کلومبیا)

30 شهریور 1402
11:00 تا 12:00

لختی اسپین ذاتی

سخنران: محمد باقرپور, دانشگاه خوارزمی

30 شهریور 1402
10:00 تا 12:00

Let $R$ be a commutative Noetherian ring and $M$ be an $R$-module. The trace of $M$, denoted by $ r_R(M)$, is defined as the sum of ideals $phi(M)$, where the sum is taken over all $R$-module homomorphisms $phi:Mlongrightarrow R$. The trace of a module have been considered in various contexts, in particular to better understand the center of the ring of endomorphisms of a module. When the canonical module $omega_R$ of $R$ exists, the significance of the trace of $omega_R$ arises from the fact that it describes the non-Gorenstein locus of $R$. The study of commutative rings lying between Gorenstein and Cohen-Macaulay rings has been very intense in the last years. There are several different ways to approach this study. One of them was recently initiated by Herzog, Hibi, and Stamate in [2] introducing the notion of nearly Gorenstein ring. A Cohen-Macaulay local ring $R$ admitting a canonical module $omega_R$ is said to be nearly Gorenstein if $ r(omega_R)$ contains the maximal ideal (there is a similar notion for positively graded algebras over a field). In these talks, we study the trace ideal of semidualizing modules, give some characterizations of them and compare them with annihilators of specific Ext modules. Then, two new classes of rings, namely quasi nearly Gorenstein and weakly nearly Gorenstein, are introduced as generalizations of nearly Gorenstein rings; [1].
references:
1. M. Bagherpoor and A. Taherizadeh. Trace ideals of semidualizing modules and two generalizations of nearly Gorenstein rings, Communications in Algebra {51}(2) (2023), 446-463.
2. J. Herzog, T. Hibi, and D. I. Stamate. The trace of the canonical module. Isr. J. Math. 233 (2019), 133-165.
3. H. Lindo, Trace ideals and centers of endomorphism rings of modules over commutative rings, Journal of Algebra {482} (2017), 102-130.
online in Zoom: https://zoom.us/join
Meeting ID: 9086116889
Passcode: 362880
Venue: Niavaran, Lecture Hall 2

سخنران: دکتر حسین کریمی (پژوهشکده ذرات و پروژه شتابگر - پژوهشگاه دانشهای بنیادی)

29 شهریور 1402
11:00 تا 12:00

مقدمه‌ای بر سیستم‌های خلاء بسیار زیاد در شتابگرهای ذرات

سخنران: مهدی حبیبی

29 شهریور 1402
14:00 تا 15:00

چکیده:

Macroscale chains have been proposed to give insight into the physics of molecular polymer systems. However, using the concept of thermodynamics for such macroscopic out-of-equilibrium systems is a matter of open debate. On the other hand, understanding the rheological response of systems of quasi-one-dimensional semiflexible materials, such as bead-chain packings, is currently a great challenge. In this talk, we study the dynamics of a single macro scale chain and an assembly of entangled chains in two different geometries and try to compare our findings with polymer physics when it is possible. For the entangled chain system, we observe a universal transition from localized to wide shear zones, that occurs upon shearing the system. We show that the nonlinear rheological response is governed by the interplay between increasing stored elastic forces due to entanglements and interlocking between chains. The insight from this study can be used as a guide to design the microstructure of new materials with peculiar mechanical responses.


برای شرکت در این وبینار وارد لینک زیر شده و به صورت میهمان لاگین کنید


https://www.skyroom.online/ch/schoolofnanoscience/weeklyseminars

سخنران: دکتر رضا جعفری (پژوهشگاه دانشهای بنیادی)

27 شهریور 1402
11:00 تا 12:00

باریون ها از مزون ها: دیدگاه یادگیری ماشینی



Link: https://meet.google.com/fnv-dfkk-ghb

سخنران: دکتر هادی محراب پور - دانشگاه گوتنبرگ

22 شهریور 1402
11:00 تا 12:00

بررسی تغییر شکل ذاتی هسته ای بوسیله همبستگی های جریانی


Link: https://meet.google.com/fnv-dfkk-ghb

سخنران: M. Ekhterachian, Theoretical Particle Physics Laboratory (LPTP), Institute of Physics, EPFL

21 شهریور 1402
14:30 تا 15:30

Date and time

Tuesday, 12th September 2023 (21th of Shahrivar, 1402), 2:30 pm (Tehran zone)



Link

https://www.skyroom.online/ch/schoolofphysics/highenergyseminar



Abstract
I will discuss a mechanism for baryogenesis from out of equilibrium decays of particles into (unparticle) states of a nearly conformal sector, applicable to composite Higgs model. The generation and evolution of the slowly varying charge and particle number densities can be described by a set “Boltzmann equations” whose coefficients can be expressed in terms of CFT correlation functions. I will apply this formalism to high scale leptogenesis in composite Higgs models and evaluate the asymmetry generation before the confining phase transition (PT) during which the composite Higgs is formed. I will then discuss how the PT may be analyzed and consider its effects on the matter abundances. The cosmological PT in the minimal models tend to complete only after a large period of supercooling, potentially resulting in excessive dilution of matter abundances. However, I will show how generic modification of the minimal models can result in a much faster completion of the PT, allowing for compatibility with baryogenesis before the PT.

Link: https://www.skyroom.online/ch/schoolofphysics/highenergyseminar

سخنران: M. Rezaie, Kansas State University & The Ohio State University

14 شهریور 1402
14:00 تا 15:00

Date and time

Tuesday, 5th September 2023 (14th of Shahrivar, 1402), 2:00 pm (Tehran zone)



Link

https://www.skyroom.online/ch/schoolofphysics/highenergyseminar



Abstract
While early studies of the cosmic microwave background and large-scale structure suggested that primordial fluctuations are both Gaussian and scale-invariant, some alternative classes of inflationary models predict different levels of non-Gaussianities in the primordial gravitational field. Local primordial non-Gaussianity (PNG) generates a primordial bispectrum, which peaks in the squeezed triangle configuration where one of the modes is on a much larger scale than the other two. The long wavelength mode couples with the other two to generate a non-Gaussian signal, which then affects the local number density of galaxies and induces a scale-dependent feature in the two-point function of galaxies. Nevertheless, probing PNG with this technique is limited by various imaging systematic effects that can modulate the galaxy power spectrum on large scales. Systematics cause wide-angle variations in the galaxy density field, and in general, any large-scale variations can translate into an excess signal in the power spectrum, which can be misinterpreted as the signature of non-zero PNG. In this talk, I present a careful study of PNG with photometric galaxies from the Dark Energy Spectroscopic Instrument Legacy Imaging Surveys. I elaborate on statistical tools and simulation-based methods to assess the significance of remaining systematic error and data quality for such a subtle measurement.

Link: https://www.skyroom.online/ch/schoolofphysics/highenergyseminar

سخنران: آقای امیرحسین موسوی (پژوهشگاه دانش های بنیادی، پژوهشکده ذرات و شتابگرها)

13 شهریور 1402
11:00 تا 12:00

طراحی کاواک موج ایستاده یازدی سلولی دوگانگی زنجیره¬های کاواک های جفت شده و سیستم های جرم-فنر دوگانگی پلاسمای غیر خنثی و معادله موج به¬عنوان یک فرضیه

Link: https://meet.google.com/fnv-dfkk-ghb

سخنران: دکتر غدیر جعفری - پژوهشگاه دانشهای بنیادی

9 شهریور 1402
11:00 تا 12:00

اثر محیط در مدل های ماتریس تصادفی با بررسی پیچیدگی و فاکتور فرم طیفی



Link: https://meet.google.com/fnv-dfkk-ghb

سخنران: دکتر محمد اسدی - پژوهشگاه دانشهای بنیادی

8 شهریور 1402
11:00 تا 12:00

رفتار اشوب در نزدیکی نقطه بحرانی



Link: https://meet.google.com/fnv-dfkk-ghb