3 AUG 2021
14:00 - 15:00

Abstract:
The idea of with EW-$\nu_R$ model with additional GeV scale mirror fermions and the extended scalar sector is very appealing. This model has a very rich scalar sector, consistent with various experimental constraints, predicts a 125 GeV scalar with the SM Higgs characteristics satisfying the current LHC Higgs boson data. A complex singlet scalar in this model helps to solve the strong-CP problem without an axion. In this work, we study the detailed scalar mass spectrum, having 125 GeV Higgs-like scalar, which is allowed by the present experimental constraints. Besides explaining the Higgs-like scalar, we find that the imaginary part of the complex singlet scalar can serve as a viable non-thermal feebly interacting massive particle (FIMP)-DM candidate. The DM can naturally be a light sub-MeV particle due to its nature as a pseudo-Nambu-Goldstone (PNG) boson. We identify the region of the parameter space for the Freeze-in mechanism scenario and find that it is consistent with the bounds from relic density and direct-indirect searches.


Date: Tuesday, August 3th
2 p.m (Tehran time)


Zoom. (click)
Meeting ID: 852 2084 9072
Passcode: 342578

29 JUL 2021
18:00 - 20:00

Commutative algebra over polynomial rings with real exponents has become important in the past decade because of its entrance into noncommutative and nonrational toric geometry as well as applications in topological data analysis. Both of these settings specifically deal with multigraded modules over real-exponent polynomial rings. But essentially nothing has been known about real-exponent algebra, in part because noetherian hypotheses fail spectacularly: monomial ideals can be uncountably generated; the quotient modulo a monomial ideal can fail to contain even a single copy of the quotient modulo any prime ideal; all positive powers of the unique maximal graded ideal are equal to one another. What should Nakayama's lemma say in a setting where finite generation can never be expected? How can primary decomposition work when modules need not contain copies of quotients modulo primes? Even more fundamentally, what kind of finiteness should prevail given the abject failure of noetherianity? Thinking geometrically about the algebra of monomial ideals with real exponents leads the way to complete, satisfying answers to all of these questions. The lessons learned reflect back on improved ways to think about aspects of ordinary noetherian commutative algebra, such as what it means for a primary decomposition to be minimal and why that question is directly to dual to Nakayama's lemma. The mathematics here is a summary of arXiv:math.AT/2008.03819
If you're interested, here are some warm-up exercises. In the two-variable real-exponent polynomial ring, find an ideal that is minimally generated by uncountably many monomials. Instruct a computer how to store your ideal. Compute a resolution of your ideal. Does your ideal have a primary decomposition? Show that the ideal of all real-exponent polynomials with constant term 0 is maximal and generated by countably many monomials, although it does not admit a minimal generating set. Do the same for the ideal of all real-exponent polynomials with no pure powers of (say) the first variable, but with ``prime" instead of ``maximal". It is not at all necessary to do these exercises to understand the talk, but they'll help you appreciate what's going on.

https://us06web.zoom.us/j/9086116889?pwd=TnhBUllnQlkwYXR4OWMxOHpjUSsyUT09
Meeting ID: 908 611 6889
Passcode: 210810

28 JUL 2021
11:00 - 12:00

Abstract: This work presents an equation of state at finite temperature and finite chemical potential using the PNJl model. The equation of state goes to the next to leading order O(1/N_c) including mesons participating to the pressure of the medium below T_c.Together with a new parametrisation of the effective Polyakov loop involving the presence of quarks in the determination of the critical temperature, is determined a pressure at zero chemical potential matching the result of the lattice and expand to finite chemical potential. Also derivatives as the entropy density, energy density, measured interaction and speed of sound are very similar to lattice results at zero chemical potential and can be expanded to finite chemical potential. Regarding the finite chemical potential, the Taylor expansion around zero chemical potential also matches the results of the lattice calculations and the low temperature and large chemical potential pressure is in agreement with pQCD calculations. This new parametrised pnjl model allows for the calculation of elastic cross sections entering the computation of the transport coefficients of the QGP at finite temperature and chemical potential in the relaxation time approximation.
Based on:
doi:10.1103/PhysRevC.101.065203 [arXiv:1908.08122[hep-ph]]

doi:10.1103/PhysRevC.103.054901 [arXiv:2011.03505[nucl-th]]



Indico: https://indico.particles.ipm.ir/indico/event/420
https://meet.google.com/qhf-iygy-pch

28 JUL 2021
14:00 - 15:00

Abstract:

Active matter is referred to a wide class of nonequilibrium systems, whose constituent particles use ambient free energy and convert it to self-propelled motion. Such active particles are commonplace in biology and include microswimmers such as bacteria, algae and spermatozoa that swim in fluid media. Active particles are also made artificially and serve numerous applications across the whole range of nano to micrometer scales, with the relevant examples furnished by self-propelled nano and micromachines. Due to its out-of-equilibrium nature and rich theoretical and experimental aspects, active matter has attracted a lot of attention from physicists in recent years. In our recent works, we have studied the active pressure and effective interactions experienced by external bodies (such as colloidal inclusions) immersed in an active fluid, consisting specifically of active Brownian disks or rods. We have thus uncovered salient effects due to permeability of the inclusions, spatial heterogeneity of the motility field experienced by the self-propelled particles, and shape of the self-propelled particles themselves.


Date: Wednesday, July 28, 2021

Time: 14:00-15:00

To join the webinar, please follow this link:
https://www.skyroom.online/ch/schoolofphysics/condensed-matter-and-statistical-physics
and log in as guest.

Organized by: Condensed Matter and Statistical Physics Group, School of Physics (IPM)

Queries about this event should be addressed to Dr. A. Faridi at azadeh.faridi@ipm.ir

27 JUL 2021
15:00 - 16:00

Abstract: Some theories of gravity are thought to be dual to an ensemble of quantum systems. I will talk about how this interpretation can teach us about gravity. First, I will comment on the constraints from the ``moments problem'' and application of that in some simple 2-dimensional theories of gravity. Second, I will use the duality between JT gravity and a matrix ensemble (due to Saad, Shenker, and Stanford) to compute the low-temperature entropy of JT gravity.

27 JUL 2021
15:00 - 16:00

Abstract:

Some theories of gravity are thought to be dual to an ensemble of quantum systems. I will talk about how this interpretation can teach us about gravity. First, I will comment on the constraints from the ``moments problem'' and application of that in some simple 2-dimensional theories of gravity. Second, I will use the duality between JT gravity and a matrix ensemble (due to Saad, Shenker, and Stanford) to compute the low-temperature entropy of JT gravity.



Date: Tuesday, July

3 p.m (Tehran time)





Zoom. (click)

Meeting ID: 814 2211 5396

Passcode: 462136

26 JUL 2021
11:00 - 12:00

Based on
https://sciendo.com/article/10.1515/nuka-2016-0002


Abstract: Intraoperative electron radiation therapy (IOERT) is a cancer treatment method that combines oncologicsurgery with electron beam radiotherapy. Thismethod can reduce the duration of entire tumor treatment andincrease its effectiveness. Moreover, shortening the treatment time significantly reduces thecost and accessibilityof the therapy. As a result of interdisciplinary research, aninnovative accelerator for IOERT, the Intra-Line, wasdeveloped. In the course ofthis work, four patent applications were fi led. Today, the work is half waythrough.In the near future, the device will be optimized. New mechanical designsolutions will be developed. Mechanicaloptimization will significantly reduce the weight of the device. Accelerators control system, which today is inthe demophase, will also be significantly upgraded. This paper describes the stages of theIntra-Line acceleratordevelopment, its current state and plans for the future R&D work, within the scope of our new Intra-Dose project.


https://meet.google.com/ijy-hspi-aua

22 JUL 2021
11:00 - 13:00

The concept of base is crucial to study representations of affine Lie (super)algebras. In 2010, this concept was defined by V. Serganova. In her definition, the algebraic structures get involved. We define a base in a combinatorically manner and show that this new definition coincides with the previous one for twisted affine Lie superalgebras and then classify them.

https://zoom.us/j/9086116889?pwd=TnhBUllnQlkwYXR4OWMxOHpjUSsyUT09
Meeting ID: 908 611 6889
Passcode: 210810

20 JUL 2021
14:00 - 15:00

Abstract:

Axion warm inflation has been introduced as an alternative to standard (cold) inflation. Coupling between inflaton (axion) field and gauge fields changes the evolution of scalar field even at the background level. It was discussed that the system with this coupling can be thermalized inherently and is protected against tachyonic instability. I will discuss that this scenario is compatible with observation and is in the landscape of quantum gravity conjectures.


Date: Tuesday, July 20th

2 p.m. - 3 p.m. (Tehran time)

Zoom. (click)

Meeting ID: 852 2084 9072

Passcode: 342578

19 JUL 2021
11:00 - 12:00

Based on
https://arxiv.org/pdf/2106.03964.pdf


Abstract: The Goheer-Kleban-Susskind no-go theorem says that the symmetry of de Sitter space is incompatible with finite entropy. The meaning and consequences of the theorem are discussed in the light of recent developments in holography and gravitational path integrals. The relation between the GKS theorem, Boltzmann fluctuations, wormholes, and exponentially suppressed non-perturbative phenomena suggests: the classical symmetry between different static patches is broken; and that eternal de Sitter space - if it exists at all - is an ensemble average.


https://meet.google.com/ijy-hspi-aua