21 MAY 2025
18:00 - 19:30

Date and time,


6-7:30pm, Wednesday 21 May 2025 (31 Ordibehesht 1404)


Venue: Online



Link

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



Abstract


I will argue that the usual effective field theory techniques break down in the rapdily expanding background of the early universe. The TCC ("Trans-Planckian Censorship Criterion") plays a key role in the argument. I will then discuss an attempt to obtain an emerging metric space-time and early universe cosmology starting from a quantum mechanical matrix model.

21 MAY 2025
12:30 - 13:30

Abstract:

In this lecture, I will discuss recent efforts on discovery of black holes. I will also explain and elaborate on cases in which I have contributed in these discoveries.

Poster:
https://particles.ipm.ac.ir/pdf/poster_drrahvar.pdf

Indico Link:
https://indico.hep.ipm.ir/e/s.rahvar

Meeting Place:
Seminar Room, School of Particles and Accelerators, IPM

Link to Join Virtually:
https://www.skyroom.online/ch/ipm-particles/special-seminar

21 MAY 2025
16:00 - 17:00

The emergence of AI, particularly large language models (LLMs), has dramatically reshaped the requirements for error-correcting codes, particularly in the realm of memory I/O during training. Massive data transfers involved in training LLMs necessitate extremely robust error correction to prevent costly retraining scenarios triggered by undetected errors (Silent Data Corruption). Traditional iterative decoding techniques are inadequate due to their latency constraints, pushing the field towards combinational logic implementations capable of achieving multiple-error correction under extremely tight latency budgets. Algebraic codes, which once seemed to have lost ground to iterative decoding algorithms, are experiencing a renaissance driven by these stringent AI-driven performance demands. By exploiting deep results from algebra, notably Galois theory, algebraic codes are now being implemented in fully combinational hardware circuits that offer both the necessary decoding speed and robust error-correction guarantees. This development underscores algebraic coding theory?s renewed relevance and critical importance for future high-performance AI systems​.

Subscribing the Mathematics Colloquium mailing list:
https://groups.google.com/g/ipm-math-colloquium
Venue: Niavaran, Lecture Hall 1

21 MAY 2025
13:30 - 15:00

21 MAY 2025
14:00 - 15:00

Retinal neovascularization is a major cause of irreversible vision impairment in the elderly. The current first-line treatment involves the intravitreal administration of anti-vascular endothelial growth factor (anti-VEGF) agents to inhibit abnormal blood vessel growth in the retina. While initially effective, some patients experience a progressive decline in response to anti-VEGF therapy after repeated administrations. This diminishing efficacy is often attributed to the development of resistance through overlapping and compensatory pathways. Future therapeutic strategies may focus on identifying novel targets, rewiring pathological signaling networks, and designing innovative molecules capable of simultaneously inhibiting multiple pathways involved in neovascularization. Additionally, the identification of diagnostic biomarkers and the development of advanced therapeutic interventions will greatly benefit from systems biology approaches that integrate multi-omics data. Such strategies hold the potential to pave the way for more personalized and effective treatments for retinal diseases.


This Seminar is free, hybrid, and open to the public.

21 MAY 2025
14:00 - 15:00

This talk explores the ground state phases of a spin-1/2 Kekule-Heisenberg (KH) model, a generalization of the Kitaev model on a honeycomb lattice, a key interest in condensed matter physics. The goal is to identify quantum paramagnetic phases like spin liquids and valence bond solids, which, despite lacking magnetic order, hold significant potential for different applications. Using a graph-based projected entangled pair state (gPEPS) method in the thermodynamic limit, the study mapped the model's phase diagram, revealing various phases including a valence bond solid (VBS) with zero magnetization, ferromagnetic and Neel ordered phases, and a Kitaev spin liquid. Notably, the VBS phase preserves all symmetries of the initial Hamiltonian but features a unique plaquette order with decorated plaquettes, distinguishing it from conventional quantum spin liquids. These findings deepen understanding of complex magnetic phases relevant for future quantum technologies.


Venue: Room D, 3rd Floor, Farmanieh Building, IPM
Link: https://vmeeting2.ipm.ir/b/nan-gkn-wmh-exh

20 MAY 2025
14:00 - 15:00

Date and time

Tuesday, May 20th, 2025 (30 Ordibehesht), 2:00 pm (Tehran zone)




Link

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


Abstract
High-energy neutrinos are extremely valuable cosmic messengers, as they not only carry unique information about the most extreme astrophysical environments, but also provide an opportunity to probe different aspects of particle physics. When talking about extremes, the ultra-high-energy neutrino event KM3-230213A, recently reported by the KM3NeT collaboration, stands out due to being the most energetic event ever observed, lying in the multi-PeV to EeV range. This observation is remarkable in itself, but several questions arise due to the non-observation of similar events at the IceCube neutrino observatory, which has been running for longer with a larger effective area. In this talk, I will try to confront the KM3-230213A event with IceCube data in the context of different hypotheses about its origin. I will focus on discussing the different tensions and difficulties that arise when trying to place this event in the global high-energy neutrino picture.

19 MAY 2025
16:30 - 18:00

Not So Fast; An Avicennian Defense of Necessitarianism

https://meet.google.com/szz-ogik-tyn

19 MAY 2025
11:00 - 12:00

Abstract:

In this paper, they consider top quark decay in the standard model effective field theory (SMEFT). They present a calculation of the total decay width and the W-boson helicity fractions at next-to-leading order (NLO) in SMEFT. Their result includes the complete set of contributing four-fermion operators in addition to QCD dipole operators and bottom-mass suppressed effects. They show that operators that first appear at NLO in the SMEFT can be bounded by the current data as well as future data from both a high-luminosity LHC and a potential e+e− collider, demonstrating the importance of going beyond leading order when studying the SMEFT. They discuss technical aspects of Their calculation that They believe will be useful in future higher-order studies of the SMEFT, in particular, the treatment of γ5 in loop diagrams.

Based on:
https://arxiv.org/abs/1907.00997

Meeting Place:
Seminar Room, School of Particles and Accelerators, IPM

Link to Join Virtually:
https://www.skyroom.online/ch/ipm-particles/journal-club

18 MAY 2025
11:00 - 12:30

Abstract:
I will talk about a work in progress about dispersion relations and tidal deformability of compact objects. Tidal Love number coefficient is given in terms of the two point function of the stress tensor. These are similar to the electromagnetic polarizability of an object. By using the conditions of causality and positivity one can prove positivity bounds on the Love number of weakly gravitating compact objects.

15 MAY 2025
14:00 - 16:00

An imaginary sort of a first-order structure is a possible universe of an interpretable structure. The significance of imaginary sorts was established in the abstract setting of Classification Theory by Shelah, where all notions of stability theory, especially algebraic closure, were interpreted with imaginary sorts taken into account. Imaginaries were studied for specific theories by Poizat who showed that algebraically closed fields and differentially closed fields eliminate imaginaries, i.e. each imaginary sort is in definable bijection with a definable set of n-tuples. In valued fields imaginary sorts differ qualitatively from definable sets; an example is the value group. In this case it is a question of finding a useful basis for the imaginary sorts, meaning that every imaginary sort can be embedded into a product of basis elements. A basis for imaginary sorts for algebraically closed valued fields was given by Haskell-Hrushovski-Macpherson. Rideau-Hrushovski-Martin, and more recently Hils-Rideau-Kikuchi, proved that for the field of $p$-adic numbers the $p$-adic lattices provide a basis for imaginary sorts.
In this talk I will describe joint work with Ehud Hrushovski which gives a description of imaginary sorts and their basis for products and restricted products of structures in terms of a basis for imaginary sorts for the factors. In 1959 Feferman and Vaught proved that the theory of a product is determined by the theory of the factors and the theory of the Boolean algebra of subsets of the index set. This yields decidability results and descriptions of definable sets for products in terms of the factors. Our results show that imaginaries also admit a description relative to the factors. The proofs use tools from geometric stability theory including liaison groups, and descriptive set theory of smooth Borel equivalence relations, including a dichotomy theorem due to Harrington-Kechris-Louveau and Glimm-Efros. As an application, we describe a basis for the imaginary sorts for the ring of adeles of rational numbers in terms of the family of $p$-adic lattices for �almost all� $p$, and prove weak elimination of imaginaries for the adeles in these sorts.

Joint work with: Ehud Hrushovski
Zoom room information:
https://us06web.zoom.us/j/81916335336?pwd=5zQT4lutMiBoY5Xp1pkFGtbqiaGozg.1
Meeting ID: 819 1633 5336
Passcode: 559618
Venue: Niavaran, Lecture Hall 1

14 MAY 2025
14:00 - 15:00

Retinal degenerative diseases including neovascular age-related macular degeneration (nAMD), diabetic retinopathy (DR), glaucoma, and retinitis pigmentosa (RP) are major global causes of vision loss. Current therapies, such as anti-VEGF treatments, face limitations due to biological complexity, treatment resistance, and delivery challenges. Our research integrates systems biology, molecular engineering, and gene therapy to address these gaps. We identify key molecular hubs and pathways, develop next-generation anti-angiogenic agents (hinge-truncated sFLT01), and design novel peptide-based gene delivery system (MiRGD) that enhances targeting and biocompatibility. Additionally, we explore optogenetic tools, ER stress modulation, and retinal regeneration strategies to advance therapeutic options. Our multidisciplinary approach offers promising avenues for safer, more effective treatments and deepens the understanding of retinal disease mechanisms.


This Seminar is free, hybrid, and open to the public.

14 MAY 2025
11:00 - 12:00

Abstract:

This talk addresses key challenges in modern cosmology and introduces the motivations for a "void-based cosmology". In this approach, voids (bubbles) are treated as independent, dynamic components of the cosmic web next to clusters (drops). Drawing inspiration from the behavior of heated milk overflowing, the presentation will examine the connection between void surface tension and the cosmological constant, the modified uncertainty principle, and the evolving dark energy density resulting from void mergers on cosmic scales.

Indico Link:
https://indico.hep.ipm.ir/e/e.yusofi

Link to Join Virtually:
https://www.skyroom.online/ch/ipm-particles/weekly-seminar

14 MAY 2025
14:00 - 15:00

For any k + 1 ≥ 3 positive integers t, n_1, . . . , n_k, there exists a positive integer N such that if every t-element subset of the set {1, . . . , N} is colored using one of the k colors 1, . . . , k, then there exists an index i ∈ {1, . . . , k} and a subset S ⊆ {1, . . . , N} with |S| = n_i, such that every t-element subset of S is colored with color i. This is a generalization of Ramseys Theorem, which is often formulated in the language of graph theory by:
? interpreting {1, 2, . . . , N} as the vertex set of the complete graph K_N,
? considering the case t = 2, and
? coloring each 2-element subset (edge) with one of k colors.
Ramseys Theorem then implies that for any two positive integers s and t, there exists a minimum integer N such that in any red-blue coloring of the edges of K_N , one can find either a red complete subgraph Ks or a blue complete subgraph Kt. The smallest such N is known as the Ramsey number R(s, t), or more generally R(G, H) when considering arbitrary graphs G and H. Several variants of Ramsey numbers have been developed. Notably, the bipartite Ramsey number, the multipartite Ramsey number, the m-bipartite Ramsey number, and the pair bipartite Ramsey number extend the classical notions to bipartite and multipartite settings.
In this talk, we will present recent results concerning some of these extended versions. In particular, we will focus on:
? The multicolor bipartite Ramsey number BR(G_1, G_2, . . . , G_t), defined as the smallest integer n such that any t-edge-coloring of the complete bipartite graph K_{n,n} contains a monochromatic copy of G_i for some 1 ≤ i ≤ t.
? The pair bipartite Ramsey number Bp(G_1, G_2) = (a, b), the smallest ordered pair such that every red-blue edge-coloring of K_{c,d} with c ≥ d guarantees a blue copy of G_1 or a red copy of G_2, provided c ≥ a and d ≥ b.

Zoom room information:
https://us06web.zoom.us/j/84906984159?pwd=BCWaIbXBuku3A5I84zNg9mHFxVZjXD.1
Meeting ID: 849 0698 4159
Passcode: 362880
Venue: Niavaran, Lecture Hall 1

14 MAY 2025
17:30 - 19:00

I will start with a review of KSB/A stability, especially their local version and then discuss joint work with Janos Kollar, showing that it is enough to check these conditions, including flatness, up to codimension 2. This implies that we have a very good understanding of this stability condition in general, because local KSB-stability is trivial at codimension 1 points, and quite well understood at codimension 2 points, since we have a complete classification of 2-dimensional slc singularities.

Venue: online
https://zoom.us/join
Meeting ID: 9086116889
Passcode: 362880
Website: http://math.ipm.ac.ir/agnt/
Venue: , (Online)