2 OCT 2024
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IRCHEP 1403
Iranian Conference on High Energy Physics
Deciphering the Universe Ciphers
School of Physics, IPM
September 30th-October 2nd, 2024 (9-11 Mehr,1403)

2 OCT 2024
11:00 - 12:00

Abstract:

The structure of the beta-expanded representations for the coefficients of the perturbative QCD series for the e^+e^-- annihilation Adler function and Bjorken polarized and Gross-Llewellyn Smith neutrino DIS sum rule is analysed. The product of the series for the Adler function and these Deep-inelastic scattering sum rules obeys the generalized Crewther relation, which reflects the manifestation pf the proportional to the RG Beta-function conformal symmetry breaking perturbative contribution into the amplitide of pi- gamma gamma decay / The relation of the beta-expanded represntations for these series to proper treatment of the renormalon free PT QCD variants pf the Brodsky-Lepage-Mackenzie scale fixing procedure is discussed. The relation to the perturbative quenced QCD and finite QED limits expressions, which are realized in the non-distingushed in the experimentally related conformal symmetry limit considerations is clarified.

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

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

2 OCT 2024
14:00 - 15:00

‎A signed graph is a pair $G_{\sigma}=(G‎, \sigma)$‎, ‎where $G$ is a simple graph and $\sigma$‎, ‎called the signature‎, ‎is a function which assigns 1 or $-1$ to each edge of $G$‎. ‎We call $\sigma$ as an it orthogonal signature of $G$ if‎ $A(G_{\sigma})^2=D$‎, ‎where $A(G_{\sigma})$ is the signed adjacency matrix of $G_{\sigma}$ and $D$ is the diagonal matrix with vertex degrees on the diagonal‎.
‎We have shown that if $G$‎ has an orthogonal signature‎, ‎then $G$ should be regular‎.


‎Graphs with orthogonal signature were crucial in the proof of sensitivity conjecture by Huang in 2019‎. ‎Hunag used an orthogonal signature of hypercube in his proof‎. Alon and Zheng extended it from hypercubes to Cayley graphs of $\mathbb{Z}^{n}_2$‎. ‎Other researchers had considered signed graphs with just two distinct eigenvalues‎. ‎Note that the signed adjacency matrix of an orthogonal signature‎
‎of a $k$-regular graph has only two distinct eigenvalues which are $\pm \sqrt{k}$‎. ‎We also note the signed adjacency matrix of any signature‎ of a $k$-regular graph has spectral radius in the interval $[ \sqrt{k},k]$‎. ‎So an orthogonal signature has the minimum spectral radius among all signatures of a regular graph‎. Orthogonal signatures have been classified for $3$-regular and 4-regular graphs‎. ‎A partial answer for 5-regular graphs is given by Stanic‎.


‎We will discuss general constructions for graphs with orthogonal‎
‎signature and also the classification of orthogonal signatures of $k$-regular‎
‎graphs for a fixed $k$‎, ‎specially for $k = 5‎, ‎6$‎.
‎This is a joint work with Bojan Mohar and Maxwell Levit‎.





Zoom room information:


https://us06web.zoom.us/j/85237260136?pwd=MFSZoKdmRXAjfaSaBzbf19lTaaKglf.1


Meeting ID: 852 3726 0136


Passcode: 362880
Venue: Niavaran, Lecture Hall 1

1 OCT 2024
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IRCHEP 1403
Iranian Conference on High Energy Physics
Deciphering the Universe Ciphers
School of Physics, IPM
September 30th-October 2nd, 2024 (9-11 Mehr,1403)

30 SEP 2024
-


IRCHEP 1403
Iranian Conference on High Energy Physics
Deciphering the Universe Ciphers
School of Physics, IPM
September 30th-October 2nd, 2024 (9-11 Mehr,1403)

30 SEP 2024
11:00 - 12:00

Abstract:

QCD monopoles are magnetically charged quasiparticles whose Bose-Einstein condensation (BEC) at TTc plays an important role in explaining the properties of strongly coupled quark-gluon plasma (sQGP) near the deconfinement temperature. In this paper, we study the phenomenon of chiral symmetry breaking and its relation to magnetic monopoles. Specifically, we study the eigenvalue spectrum of the Dirac operator in the basis of fermionic zero modes in an SU(2) monopole background. We find that as the temperature approaches the deconfinement temperature ω=0 from above, the eigenvalue spectrum has a finite density at ω=0, indicating the presence of a chiral condensate. In addition, we find the critical scaling of the eigenvalue gap to be consistent with that of the correlation length in the 3d Ising model and the BEC transition of monopoles on the lattice.

Based on:
https://arxiv.org/abs/1801.06922

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

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

27 SEP 2024
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https://physics.ipm.ac.ir/conferences/ishep2024/index.jsp

26 SEP 2024
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https://physics.ipm.ac.ir/conferences/ishep2024/index.jsp

25 SEP 2024
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https://physics.ipm.ac.ir/conferences/ishep2024/index.jsp

25 SEP 2024
13:30 - 15:00

In this talk we continue our studies of the quantum loop corrections in models of single field inflation employed for generating primordial black holes. Calculating the cubic and quartic Hamiltonians, we study the loop corrections in the power spectrum and bispectrum and investigate various physical implications.

25 SEP 2024
11:00 - 12:00

Abstract:

Recently, and due to some experimental observations, such as the collectivity in the collision of small hadrons like proton+proton or proton+lead, the use of Relativistic Hydrodynamics in its old form in modeling the collision of heavy ions has encountered some challenges. We will discuss these challenges and also address the new observations in the collision of small systems. We will then show how we can bring together the fluctuation and the analytical requirements to reproduce the real propagation modes. The role of the fluctuation is crucial and it turns out that with its help we can make the non-hydrodynamic modes in such systems vanish or fade out.

Based on:
https://arxiv.org/abs/2408.01742

Indico Link:
https://indico.hep.ipm.ir/e/f.taghinavaz1

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

Link to Join Virtually:
https://meet.google.com/bda-vsem-tuv

25 SEP 2024
16:00 - 17:00

حدس الیوت در سال 1990 مطرح شد و پیش بینی می کرد که کلاس سی استار جبرهای جدایی پذیر یکدار ساده میانگین پذیر با استفاده از پایاهای K-نظریه قابل طبقه بندی هستند. این حدس بر پایه نتایجی بود که برای کلاسهای کوچکتر اثبات شده بود. این حدس برای کلاسهای بزرگی ثابت شده است و مثالهای نقضی در سالهای 2002 و 2008 برای آن پیدا شد. برنامه طبقه بندی الیوت که از زمینه های پژوهشی پویا و گسترده در جبر عملگرها می باشد، به بررسی این حدس و کاربردهای آن در جبر عملگرها، سیستم های دینامیکی و سایر شاخه های ریاضی می پردازد. در این سخنرانی، ضمن بیان این برنامه و نتایج بدست آمده، ارتباط و کاربردهای آن در برخی از شاخه های ریاضی را شرح می دهیم.
Venue: Niavaran, Lecture Hall 1

25 SEP 2024
14:00 - 15:00

Clustering is a widely used technique in unsupervised learning to identify groups within a dataset based on the similarities of its elements. This talk introduces a novel hierarchical clustering model, specifically designed for datasets with a countably infinite number of points. The proposed algorithm employs various levels of clustering and constructs clusters at each level using nearest-neighbor chains of points or clusters. We apply this algorithm to the Poisson point process. We prove that the clustering algorithm defines a phylogenetic forest on the Poisson point process, which is a factor of the point process and is hence unimodular. Various properties of this random forest, such as the mean sizes of clusters at each level or the mean size of the cluster of a typical node, follow.

Zoom room information:
https://us06web.zoom.us/j/85237260136?pwd=MFSZoKdmRXAjfaSaBzbf19lTaaKglf.1

Meeting ID: 852 3726 0136
Passcode: 362880
Venue: Niavaran, Lecture Hall 1

23 SEP 2024
11:00 - 12:00

Abstract:

We have studied the entanglement of purification Ep in a non-conformal holographic model which is a five-dimensional Einstein gravity coupled to a scalar field ϕ with a non-trivial potential V (ϕ). The dual 4-dimensional gauge theory is not conformal and exhibits a RG flow between two different fixed points. There are three parameters including energy scale Λ, model parameter ϕM and temperature T which control the behaviour of the theory. Interestingly, we have found that Ep can be used as a measure to probe the non-conformal behavior of the theory at both zero and finite temperature.

Based on:
https://arxiv.org/pdf/2408.05522

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

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