✅ هفدهمین کنفرانس ماده چگال انجمن فیزیک ایران ۱۴۰۳

#اخبار_انجمن_فیزیک_ایران

هفدهمین کنفرانس ماده چگال انجمن فیزیک ایران روزهای ۱۰ و ۱۱ بهمن‌ماه ۱۴۰۳ در دانشگاه تبریز برگزار خواهد شد. زمینه‌های مورد بحث ابررسانایی ماده چگال نرم و بیو فیزیک درهمتنیدگی کوانتومی و سیستمهای پیچیده دستگاههای همبسته قوی و مغناطیس، مایعات کوانتومی ساختار الکترونی و خواص الکتریکی، مغناطیسی و ...

📣 متن کامل را در Instant View ⚡️ (دکمه پایین صفحه) و یا در وب‌گاه انجمن فیزیک ایران بخوانید:
🚩http://www.psi.ir/news2_fa.asp?id=4109

⏪ وب‌گاه انجمن فیزیک ایران:
🌍 http://www.psi.ir

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👇👇🏽👇👇🏽👇👇🏽👇
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School of Physics: HEPCo Weekly Seminar Series

Speaker

Saeed Abbaslu


Affiliation

School of Physics, IPM


Title of talk

A novel global charge conservation in the symmetric phase of the early Universe



یک بقای بار سراسری جدید در فاز متقارن کیهان اولیه

Date and time

Tuesday, August 27th, 2024 (Shahrivar 6th, 1403), 2:00 pm (Tehran zone)


Link

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


Abstract

In the Standard Model at high temperatures, anomalous effects contribute to the violation of baryon number ($B$) and lepton number ($L$), separately, while $B-L$ remains conserved. There are also corresponding changes in the helicity of the hypermagnetic field ($h$) and the Chern-Simons numbers of the non-Abelian gauge fields ($N_{\rm CS,W}$ and $N_{\rm CS,S}$). In this study, we investigate a baryogenesis process in the symmetric phase of the early Universe by taking into account the Abelian and non-Abelian anomalous effects as well as the perturbative chirality-flip processes of all fermions. We calculate explicitly the time evolution of all relevant physical quantities, including those of $h$ and $N_{\rm CS,W}$, and show that there is another conserved global charge involving total matter-antimatter asymmetry $B+L$, hypermagnetic helicity $h_B$ and $N_{\rm CS,W}$.

🌪 آیا ماده تاریک وجود دارد؟ حساس ترین آشکارساز جهان، LUX-ZEPLIN، قادر به یافتن ذرات WIMP نیست! 🌪

لینک گزارش
@PDATLAB

The course outline: Quantum Field Theory I, Fall 2024


This is an introductory course on quantum field theory (QFT). QFT is a fundamental requirement in the studies of theoretical high energy physics, particle physics and early universe cosmology. It is a vast and well-established subject with applications in many branches of theoretical physics and cosmology. There are many textbooks on QFT, old and new. In this course we will mainly follow the book by Peskin & Schroeder (Perseus Books, 1995). This is an excellent book, emphasizing on various aspects of QFT, both at the level of formalisms and applications. There are other useful books which may be consulted as well. For example, the book by Schwartz (Cam- bridge University Press, 2014) is very useful as well. The QFT book by Steven Weinberg (Cambridge University Press, volume I, 1995) is an excellent reference for deeper under- standings of various topics in QFT. However, because of its high level of presentation, it is not suggested as a regular text book for a first time study in QFT. This is a three-unit course. Our goal is to cover most of part I of Peskin & Schroeder, chapters 1-7.


Time and place of the course: Sunday and Tuesday, 9:00 - 10:30, IPM, School of Astronomy, Larak garden.


My Contact information Hassan Firouzjahi IPM, School of Astronomy, Larak garden e-mail: firouz@ipm.ir

🪢 مطالعه جدیدی نشان می دهد که جهان ممکن است قبل از انفجار بزرگ "زندگی مخفی" داشته باشد 🪢

لینک گزارش
@PDATLAB

🇨🇭PhD position in Planetary Atmospheres at ETH Zürich🇨🇭

Job Denoscription

The successful candidate will develop numerical models based on experiments using an aerodynamic laser-heated levitation furnace to simulate atmospheric escape in the laboratory. Velocimetry measurements will be performed in order to describe the flow of gases around a molten bead in a fluid dynamical framework. Isotopic analyses of the residues of atmospheric loss are to be undertaken to establish the pressures at the surface of the bead. These constraints will be used to develop a 3D model of atmospheric loss from planetary bodies.

Application Instructions

All applications must be submitted via the ETH online portal. The deadline for applications is the 23rd of September 2024, ideally with a start date of 1st of January, 2025. Further information about our group can be found on our website www.planetology.ethz.ch.
Link to Online Application
https://jobs.ethz.ch/job/view/JOPG_ethz_klWLnENFbWirZO2euy
Publication Start Date
2024 Aug 28
Application Deadline
2024 Sep 23

✅ جدیدترین تحلیل از داده‌های جیمز وب، نشان می‌دهد که ممکن است «تنش هابل» واقعی نباشد

#اخبار_علمی_و_پژوهشی

ما چیزهای زیادی درباره‌ی کیهان می‌دانیم، اما ستاره‌شناسان هنوز بر سر سرعت دقیق گسترش کیهان توافق ندارند. در واقع، در طول دو دهه گذشته، اندازه‌گیری آهنگ انبساط کیهان که به عنوان «ثابت هابل» شناخته می‌شود از طریق دو روش عمده به نتایج متفاوتی رسیده‌اند، که باعث شده برخی از کیهان‌شناسان به این فکر کنند ...

📣 متن کامل را در Instant View ⚡️ (دکمه پایین صفحه) و یا در وب‌گاه انجمن فیزیک ایران بخوانید:
🚩http://www.psi.ir/news2_fa.asp?id=4105

⏪ وب‌گاه انجمن فیزیک ایران:
🌍 http://www.psi.ir

✅ به کانال خبرى انجمن فیزیک ايران بپيوندید:
👇👇🏽👇👇🏽👇👇🏽👇
http://t.me/psinews

بعد از آشکارسازی امواج گرانشی، شاید در آینده نزدیک چشم‌مان به آشکارسازی «امواج ماده تاریک» روشن شود:
Searching for dark matter with a 1000 km baseline interferometer
https://arxiv.org/abs/2408.02668

در این پژوهش به جستجوی ماده تاریک با استفاده از یک نوع تداخلسنجی با خط پایه 1000 کیلومتری پرداخته شده است. اصول کار این تداخلسنج شبیه شبکه تداخلسنج های امواج رادیویی، مانند تلسکوپ افق رویداد است، با این تفاوت که این تداخلسنج به امواج ماده تاریک حساس است، نه امواج الکترومغناطیس. کوچکترین طول موج دوبروی که در این پژوهش جستجو شده است بیش از هزار برابر بزرگتر از شعاع زمین است!

در این پژوهش از دو هم‌مغناطیسسنج اتمی K-Rb-3He استفاده شده است که یکی در ماینتس آلمان و دیگری در کراکوف لهستان قرار دارد. این تداخلسنج برای بررسی برهمکنش بین ماده تاریک شبه-اکسیونی و نوکلئونها طراحی شده است. جستجو در محدوده نه مرتبه بزرگی در جرم ماده تاریک اکسیونی انجام شده است. و البته در این محدوده، هیچ شواهد قابل توجهی از سیگنال این نوع ماده تاریک یافت نشده است.

😱 نخستین هواپیمای فضایی با قابلیت حمل مسافر و بار 😱

لینک گزارش
@PDATLAB

School of Physics: HEPCo Weekly Seminar Series


Speaker

Sajad Aghapour


Affiliation

Max Planck Institute for Gravitational Physics (Albert Einstein Institute)


Title of talk

Interaction of Kerr-Newman Electromagnetic Fields



برهم‌کنش میدان‌های کر-نیومان الکترومغناطیس

Date and time

Tuesday, September 10th, 2024 (Shahrivar 20th, 1403), 2:00 pm (Tehran zone)

Link

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

Abstract

In this talk, I will discuss some properties of the Kerr-Newman (KN) Electromagnetic Fields, which is the G → 0 limit of the KN solution of Einstein-Maxwell equations. In this limit, the electromagnetic sector of the solution survives, while the background becomes locally flat with nontrivial topology. The discussion includes the complex transformation between the non-spinning Coulomb solution and the spinning KN, the g = 2 gyromagnetic ratio of the solution noted by Carter, and the corresponding multipole structure. The topological conserved charges of the electromagnetic field, i.e. the classical helicity and classical spin, are calculated for this solution. Moreover, we studied the interaction of two such solutions by evaluating the Lagrangian for the superposition of those fields. This yields a correction to the interaction potential beyond the Coulomb interaction due to the spin of the fields. The talk is based on: https://arxiv.org/pdf/2405.12602.

سلام

🔵 قابل توجه دانشجو‌های دکتری و محققان پسادکتری در گرایش ریسمان و هولوگرافی (دقت کنید این یک برنامه برای همکاری در کار تحقیقاتی نیست) :


Dear colleague,

Are you a PhD student or postdoctoral fellow who feels would benefit from guidance on your academic career, work-life balance, or other challenges from an experienced researcher within our string theory community? Or, are you a postdoc or faculty member who feels you can support a younger scientist in navigating their academic journey?

Consider applying to "Quantum Guides," a mentoring program designed specifically for the string theory community.

https://sites.google.com/view/mentoring-program-string-th/home
Applications are open until September 15. The program is open to everyone, but it is targeted to underrepresented groups.
We hope to count with you in this new academic year. Please forward this email to whoever might be interested (in particular, we seek mentors to accommodate the increasing global demand of mentees).We also apologize if you receive this email more than once.
Best regards,
Mariana Grana and Irene Valenzuela (program coordinators)



@sth_fum

🇺🇸 Post-Bac Opportunity - Junior/Assistant Specialist – The Space Sciences Laboratory 🇺🇸

As a Junior/Assistant Specialist on the UVEX project, you will be responsible for:
• Analyzing data and outputs from theoretical models.
• Writing and maintaining code for data processing and analysis.
• Attending project meetings and collaborating with team members.
• Writing documentation to support research and mission objectives.
• Presenting findings to the research team and at scientific conferences.

The position will report to Berkeley Astronomy Professor Dan Weisz.

This is an exciting opportunity to contribute to a major space mission and work alongside leading experts in the field. If you are passionate about space sciences and have a strong background in data analysis and coding, we encourage you to apply.
The UC academic salary scales set the minimum pay determined by rank and step at appointment. See the following table(s) for the current salary scale(s) for this position: https://www.ucop.edu/academic-personnel-programs/_files/2024-25/july-2024-scales/t24-b.pdf. A reasonable estimate for this position is $64,100 - $82,500

✅ غربالگری که تک فوتون‌ها را از حالت های چند فوتونی جدا می ‌کند

#اخبار_علمی_و_پژوهشی

دستگاهی که حالت‌های فوتونی را مرتب می‌کند، می‌تواند به یک جزء اصلی از کامپیوترهای کوانتومی تمام-نوری منجر شود. کنترل برهمکنش‌های بین فوتون‌ها می‌تواند به فناوری‌های جدیدی از جمله رایانه‌های کوانتومی تمام-نوری بیانجامد. ریچارد واربرتون Richard Warburton و همکارانش از دانشگاه بازل سوئیس با برداشتن ...

📣 متن کامل را در Instant View ⚡️ (دکمه پایین صفحه) و یا در وب‌گاه انجمن فیزیک ایران بخوانید:
🚩http://www.psi.ir/news2_fa.asp?id=4113

⏪ وب‌گاه انجمن فیزیک ایران:
🌍 http://www.psi.ir

✅ به کانال خبرى انجمن فیزیک ايران بپيوندید:
👇👇🏽👇👇🏽👇👇🏽👇
http://t.me/psinews

📗مقاله آموزشی «تعیّن ناقص مُدل‌ها در کیهان‌شناسی و مسئله توجیه اصل کیهان‌شناختی»

♦️فهرست مطالب:
1- تعیّن ناقص مدل‌ها در کیهان شناسی نوین
2- نقش اصل کیهان شناختی در رفع تعیّن ناقص مدل‌ها
3- بررسی شواهد و استدلال‌های موجود به نفع اصل کیهان شناختی
3- 1-‌ توجیه اصل کیهان‌شناختی برای جهان قابل مشاهده
3- 1-‌ 1- بررسی مستقیم داده‌ها
3- 1-‌ 2- آزمون اصل کیهان شناختی از راه پیامدهای آن
3- 1-‌ 3- استنتاج همگنی از همسان‌گردی
3- 2-‌ توجیه اصل کیهان‌شناختی برای کل کیهان
3- 2-‌ 1- پدید آمدن یک جهان همگن و همسان‌گرد از یک شرایط اوّلیه دلخواه و عام
3- 2-‌ 2- توان تبیینی اصل کیهان‌شناختی به عنوان شاهدی بر برقراری آن
3- 2-‌ 3- اصل کیهان‌شناختی به عنوان تعمیمی از اصل هموردایی عام
3- 2-‌ 4- استنتاج اصل کیهان‌شناختی از طریق استقراء

✍🏻حامد منوچهری کوشا
🔺تعداد صفحات: 10

🔴کانال علم، فلسفه و الهیات
🆔@TheoCosmology

🇨🇭برنامه دانشجویی دکترای سرن 2025 (فول فاند)🇨🇭

لینک گزارش
@PDATLAB

🇳🇱 PhD Program in Astronomy and Astrophysics at Leiden University 🇳🇱

Leiden Observatory invites applications for approximately 6-10 new PhD positions.

The four-year PhD program consists mostly of research under the supervision of one or more faculty members. Positions are available in all the research areas in which the Observatory is active. These include cosmology, galaxy formation and evolution, interstellar matter and star formation, stars and planetary systems, computational astrophysics, high energy astrophysics, laboratory astrophysics, astrochemistry, and instrumentation. More information about research at Leiden Observatory can be found at https://www.universiteitleiden.nl/en/science/astronomy/research

Leiden Observatory, founded in 1633, is the oldest university astronomy department in the world. With about 35 faculty, over 40 postdoctoral associates and about 65 PhD students it is the largest astronomy department in the Netherlands. Leiden is a charming university town with an international flair. Most Leiden researchers have an international background. English is the common language.

During their thesis, Leiden PhD students are paid as civil servants, which means that they earn competitive salaries (the current annual gross salary, including allowances, increases from about EUR 34,000 in year 1 to about EUR 43,000 in year 4) and are eligible for both social security and retirement benefits. PhD positions are funded for four years.

Application forms and instructions are available at https://local.strw.leidenuniv.nl/jobs/phd/. Applicants are requested to upload a curriculum vitae, a list of all university courses taken and trannoscripts of grades obtained, brief statements of research interests and experience, and the contact information for at least two referees.

School of Physics: HEPCo Weekly Seminar Series


Speaker

Nicolas Bern


Affiliation

New York University Abu Dhabi


Title of talk

From WIMPs to FIMPs with Low Reheating Temperatures


از ویمپز به فیمپز با بازگرمایش در دماهای پایین

Date and time

Tuesday, September 17th, 2024 (Shahrivar 27th, 1403), 2:00 pm (Tehran zone)


Link

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


Abstract

Weakly- and Feebly-Interacting Massive Particles (WIMPs and FIMPs) are among the best-motivated dark matter (DM) candidates. In this paper, we investigate the production of DM through the WIMP and FIMP mechanisms during inflationary reheating. We show that the details of the reheating, such as the inflaton potential and the reheating temperature, have a strong impact on the genesis of DM. The strong entropy injection caused by the inflaton decay has to be compensated by a reduction of the portal coupling in the case of WIMPs, or by an increase in the case of FIMPs. We pinpoint the smooth transition between the WIMP and the FIMP regimes in the case of low reheating temperature. As an example, we perform a full numerical analysis of the singlet-scalar DM model; however, our results are generic and adaptable to other particle DM candidates. Interestingly, in the singlet-scalar DM model with low-reheating temperature, regions favored by the FIMP mechanism are already being tested by direct detection experiments such as LZ and XENONnT.

School of Particles and Accelerators

Journal Club: Experiments & Phenomenology / Hybrid Format

Date:

Monday, Sep 16, 2024 / دوشنبه، 26 شهریور 1403

Time:

11:00 AM - 12:00 PM (Tehran time)

Speaker:

Dr. Seyedeh Sedigheh Hashemi



Affiliation:

School of Particles and Accelerators, IPM

Title:

Low-energy high-brightness electron beam dynamics based on slice beam matrix method



Title in Persian:

دینامیک بیم الکترونی کم انرژی و روشنایی زیاد با استفاده مدل ماتریسی



Abstract:

Preserving the phase space quality has been of crucial importance to high-brightness electron beam transport. Any driving source of beam performance limitations in such a transport system must be carefully examined in order to preserve the beam phase space quality. It is found that in the low beam energy, high bunch charge regime, space charge effect on the charged particle beam evolution can be complicated. It may be insufficient to analyze the beam properties through the envelope or lower order moments for the mere bulk of the beam. In this work we will study the space-charge-dominated, low-energy, high-brightness electron beam dynamics based on the slice beam matrix method. The slice beam matrix method, extended from the existing bulk beam analysis, is applicable to an arbitrary longitudinal bunch distribution and can thus take the nonlinear RF curvature into account. The semi-analytical sliced beam space charge model is constructed and assumes an axisymmetric beam in the presence of perfect conducting cylindrical pipe with circular cross section. We present in this paper the theoretical formulation, starting from single-particle dynamics, space charge field calculation, followed by the moment denoscription of a collection of particles, based on beam sigma matrix and longitudinal slice decomposition. We prove the equivalence between the beam matrix method and the envelope formalism in the presence of space charge effect, in both the transverse and longitudinal dimensions.



Based on: https://doi.org/10.1016/j.nima.2019.05.035

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

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

گروهی از دانشگاه استنفورد بستری را فراهم کرده‌اند که می‌توان برای قسمت‌های مختلف مقالات در سایت آرکایو arXiv، سوالات یا نظرات را مطرح کرد و در یک گفت و گو در این باره شرکت کرد.
متن اعلامیه شروع این بستر به شرح زیر است:

arXiv -> alphaXiv
Students at Stanford have built alphaXiv, an open discussion forum for arXiv papers.
You can post questions and comments directly on top of any arXiv paper by changing arXiv to alphaXiv in any URL!

@sth_fum

ویدیویی از فضای این بستر جدید.

@sth_fum

صرفا با تغییر
arXiv
به
alphaXiv
در صفحه مقاله مورد نظر به این محیط وارد می‌شوید. برای استفاده از این سایت باید ثبت نام کنید.

در صورتی که با پیامی مبنی بر نبودن دامنه ایمیل شما در لیست ایمیل‌های این سایت مواجه شدید صرفا عملیات ثبت نام را ادامه دهید و توجه به این هشدار نکنید.

برای نمونه من مقاله آخر ویتن را در این سایت باز کردم:
https://alphaxiv.org/pdf/2407.20964

@sth_fum