Speaker
Mohammadreza Zakeri
Affiliation
University of Kentucky
Title of talk
Does the Sun Have a Dark Disk?
آیا خورشید دارای دیسک تاریک است؟
Date and time
Tuesday, August 3rd, 2024 (Mordad 13th, 1403), 5:00 pm (Tehran zone)
Link
https://www.skyroom.online/ch/schoolofphysics/highenergyseminar
Abstract
The Sun’s oblateness has been measured using optical observations. Its gravitational quadrupole moment has been deduced through helioseismology and measurements of its gravitational effects on Mercury’s orbit. The distribution of mass within Mercury’s orbit would only impact the orbital determination, suggesting that discrepancies among various types of assessments may indicate the possible existence of a non-luminous mass. For the first time, we have developed a method to combine these differing measurements to yield new, highly sensitive constraints on the mass distribution within Mercury’s orbit. In this talk, we will show that the most precise measurements indicate the existence of a non-luminous disk within Mercury’s orbit, with a mass significantly heavier than the modeled mass for the circumsolar dust ring observed by the Solar TErrestrial RElations Observatory (STEREO) mission. This suggests a substantial dark matter contribution. Furthermore, the long-standing inconsistency between the element abundances determined from the spectroscopy of the Sun’s surface, and those inferred from its interior through helioseismology, can be reconciled if the Sun formed within a protoplanetary disk. We will discuss how our findings limit the presence of a dark disk or a spherical halo near the Sun and highlight the potential of future orbital measurements of Mercury and near-Sun asteroids to refine these constraints further.
Mohammadreza Zakeri
Affiliation
University of Kentucky
Title of talk
Does the Sun Have a Dark Disk?
آیا خورشید دارای دیسک تاریک است؟
Date and time
Tuesday, August 3rd, 2024 (Mordad 13th, 1403), 5:00 pm (Tehran zone)
Link
https://www.skyroom.online/ch/schoolofphysics/highenergyseminar
Abstract
The Sun’s oblateness has been measured using optical observations. Its gravitational quadrupole moment has been deduced through helioseismology and measurements of its gravitational effects on Mercury’s orbit. The distribution of mass within Mercury’s orbit would only impact the orbital determination, suggesting that discrepancies among various types of assessments may indicate the possible existence of a non-luminous mass. For the first time, we have developed a method to combine these differing measurements to yield new, highly sensitive constraints on the mass distribution within Mercury’s orbit. In this talk, we will show that the most precise measurements indicate the existence of a non-luminous disk within Mercury’s orbit, with a mass significantly heavier than the modeled mass for the circumsolar dust ring observed by the Solar TErrestrial RElations Observatory (STEREO) mission. This suggests a substantial dark matter contribution. Furthermore, the long-standing inconsistency between the element abundances determined from the spectroscopy of the Sun’s surface, and those inferred from its interior through helioseismology, can be reconciled if the Sun formed within a protoplanetary disk. We will discuss how our findings limit the presence of a dark disk or a spherical halo near the Sun and highlight the potential of future orbital measurements of Mercury and near-Sun asteroids to refine these constraints further.
www.skyroom.online
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Forwarded from انجمن علمی ژرفا
مدل_کیهان_شناسی_دوره_ای_همدیس_راجر_پنروز_به_زبان_ساده.pdf
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🔰 مقاله آموزشی «مدل کیهانشناسی دورهای همدیس راجر پنروز»
🔸 این نوشتار به معرفی مدل کیهانشناسی پنروز میپردازد؛ مدلی که ادعا میکند در آینده بسیار دور، کیهان از ذرات جرمدار خالی میشود، و در نتیجه از منظر همدیسی با ابتدای کیهان همارز است. بنابرین کیهان در آینده، گذشته خود را فراموش و دورههایی طولانی را به صورت متناوب تکرار خواهد کرد. همچنین به مسئله آنتروپی بسیار پایین کیهان اوّلیه و فرضیۀ انحنای ویل نیز پرداخته شده است.
👤 حامد منوچهری کوشا
▫️ برگرفته از کانال علم، فلسفه و الهیات
#مقاله_آموزشی #کیهانشناسی
🆔 @Zharfa90
🔸 این نوشتار به معرفی مدل کیهانشناسی پنروز میپردازد؛ مدلی که ادعا میکند در آینده بسیار دور، کیهان از ذرات جرمدار خالی میشود، و در نتیجه از منظر همدیسی با ابتدای کیهان همارز است. بنابرین کیهان در آینده، گذشته خود را فراموش و دورههایی طولانی را به صورت متناوب تکرار خواهد کرد. همچنین به مسئله آنتروپی بسیار پایین کیهان اوّلیه و فرضیۀ انحنای ویل نیز پرداخته شده است.
👤 حامد منوچهری کوشا
▫️ برگرفته از کانال علم، فلسفه و الهیات
#مقاله_آموزشی #کیهانشناسی
🆔 @Zharfa90
School of Particles and Accelerators
Special Seminar / Virtual Format
Date:
Monday, Aug 5, 2024 / دوشنبه، 15 مرداد 1403
Time:
10:30 AM (Tehran time)
Speaker:
Prof. Galileo Violini
Affiliation:
Co-chair of the Executive Committee of the Great Caribbean Light Source;
Former UNESCO Representative to Islamic Republic of Iran and Director of Tehran Office
Title:
Synchrotron in the Souths - A Science Diplomacy Challenge
Title in Persian:
سنکروترون در جنوب- یک چالش در دیپلماسی علمی
Abstract:
An advanced light source for research would drive growth in the Wider Caribbean region. In addition to analyzing the need for such a facility to meet Latin America's scientific priorities, the challenges to its construction are discussed. These are very similar to those faced by the African Light Source (AfLS): training of users, ensuring sustainable financing, the possibility of international financial support and the role of international organizations. This perspective of South-South cooperation has attracted the attention and support of other similar facilities, such as SESAME and LNLS, which can play an important role in training and, in the case of GCLS, in project design. The development and success of the corresponding actions, aimed at obtaining political support from the governments of the region and international organizations, mainly UNESCO, may be favored by the current political scenarios in both regions.
Link to Join Virtually: https://www.skyroom.online/ch/ipm-particles/seminar
Special Seminar / Virtual Format
Date:
Monday, Aug 5, 2024 / دوشنبه، 15 مرداد 1403
Time:
10:30 AM (Tehran time)
Speaker:
Prof. Galileo Violini
Affiliation:
Co-chair of the Executive Committee of the Great Caribbean Light Source;
Former UNESCO Representative to Islamic Republic of Iran and Director of Tehran Office
Title:
Synchrotron in the Souths - A Science Diplomacy Challenge
Title in Persian:
سنکروترون در جنوب- یک چالش در دیپلماسی علمی
Abstract:
An advanced light source for research would drive growth in the Wider Caribbean region. In addition to analyzing the need for such a facility to meet Latin America's scientific priorities, the challenges to its construction are discussed. These are very similar to those faced by the African Light Source (AfLS): training of users, ensuring sustainable financing, the possibility of international financial support and the role of international organizations. This perspective of South-South cooperation has attracted the attention and support of other similar facilities, such as SESAME and LNLS, which can play an important role in training and, in the case of GCLS, in project design. The development and success of the corresponding actions, aimed at obtaining political support from the governments of the region and international organizations, mainly UNESCO, may be favored by the current political scenarios in both regions.
Link to Join Virtually: https://www.skyroom.online/ch/ipm-particles/seminar
🇩🇪 The "International Max Planck Research School for Astronomy and Cosmic Physics at the University of Heidelberg" (IMPRS-HD) invites applications for its PhD program 🇩🇪
The school aims to offer outstanding research and training opportunities with excellent instrumental, observational, and theoretical research facilities at the Max Planck Institute for Astronomy, the Max Planck Institute for Nuclear Physics, the Astronomisches Rechen-Institut, the Landessternwarte Koenigstuhl, the Institute of Theoretical Astrophysics, and the Heidelberg Institute for Theoretical Studies.
Main research topics carried out at these institutions are planet and star formation; exoplanets and substellar objects; astrometry; formation, evolution and dynamics of galaxies and supermassive black holes; gravitational lensing; cosmology and structure formation; high energy astrophysics; and state-of-the-art instrumentation for astronomy and astroparticle physics.
The IMPRS-HD is an independent part of the Heidelberg Graduate School for Physics.
Several fellowships are available with 1600-1800 Euro monthly average net income.
Interested students are invited to apply by November 1, 2024, for the academic year starting in September 2025.
An earlier start of the thesis research is possible.
Applicants must have a Master's degree (or equivalent) in Physics/Astronomy including a corresponding thesis and a very good physics background. Applicants with a 4-yr degree in physics may be accepted conditionally.
Further details on IMPRS-HD and the application process can be found at http://www.imprs-hd.mpg.de/
The school aims to offer outstanding research and training opportunities with excellent instrumental, observational, and theoretical research facilities at the Max Planck Institute for Astronomy, the Max Planck Institute for Nuclear Physics, the Astronomisches Rechen-Institut, the Landessternwarte Koenigstuhl, the Institute of Theoretical Astrophysics, and the Heidelberg Institute for Theoretical Studies.
Main research topics carried out at these institutions are planet and star formation; exoplanets and substellar objects; astrometry; formation, evolution and dynamics of galaxies and supermassive black holes; gravitational lensing; cosmology and structure formation; high energy astrophysics; and state-of-the-art instrumentation for astronomy and astroparticle physics.
The IMPRS-HD is an independent part of the Heidelberg Graduate School for Physics.
Several fellowships are available with 1600-1800 Euro monthly average net income.
Interested students are invited to apply by November 1, 2024, for the academic year starting in September 2025.
An earlier start of the thesis research is possible.
Applicants must have a Master's degree (or equivalent) in Physics/Astronomy including a corresponding thesis and a very good physics background. Applicants with a 4-yr degree in physics may be accepted conditionally.
Further details on IMPRS-HD and the application process can be found at http://www.imprs-hd.mpg.de/
www.imprs-hd.mpg.de
IMPRS HD
Welcome to the Webpage of the International Max Planck Research School for Astronomy and Cosmic Physics at the University of Heidelberg (IMPRS HD)
🇩🇪 PhD in Astronomy / Astrophysics 🇩🇪
Call for applications / fully funded PhD grants for successful applicants
You want to boost your career in Astrophysics? Then do your PhD in one of the largest centers for Astronomy and Astrophysics in Europe and work with the leading scientists in the field to accelerate your scientific career!
The International Max Planck Research School on Astrophysics at the Ludwig Maximilians University Munich (IMPRS on Astrophysics) is soliciting applications for its PhD program. Located in the beautiful Munich-Garching area in southern Bavaria (Germany), the school offers a unique environment for graduate students due to the presence of four internationally renowned institutes which form the school:
The Max Planck Institute for Extraterrestrial Physics (MPE)
The Observatory of the University of Munich (LMU/USM)
The Max Planck Institute for Astrophysics (MPA)
The European Southern Observatory (ESO)
IMPRS offers a highly competitive PhD program, including lectures, seminars and a research project supervised by leading scientists at one of the participating institutions.
Course language is English. Students have access to the world largest ground- and spaced-based observatories and instrumentation operated by the participating institutes as well as to supercomputers for advanced numerical simulations and theoretical studies.
Applications for the PhD-program are open to students from all countries. Successful applicants will get a work contract / fellowship with a monthly income that covers the living costs. We will assist our students with all administrative matters for a smooth on-boarding. This means "Concentrate on your research -- we do the rest!"
For more details see: https://www.imprs-astro.mpg.de/
The closing date for applications for the program starting in September 2025 is November 1, 2024. If for any reason you have difficulty meeting the deadline, please inform us in advance and we will extend it upon request.
Call for applications / fully funded PhD grants for successful applicants
You want to boost your career in Astrophysics? Then do your PhD in one of the largest centers for Astronomy and Astrophysics in Europe and work with the leading scientists in the field to accelerate your scientific career!
The International Max Planck Research School on Astrophysics at the Ludwig Maximilians University Munich (IMPRS on Astrophysics) is soliciting applications for its PhD program. Located in the beautiful Munich-Garching area in southern Bavaria (Germany), the school offers a unique environment for graduate students due to the presence of four internationally renowned institutes which form the school:
The Max Planck Institute for Extraterrestrial Physics (MPE)
The Observatory of the University of Munich (LMU/USM)
The Max Planck Institute for Astrophysics (MPA)
The European Southern Observatory (ESO)
IMPRS offers a highly competitive PhD program, including lectures, seminars and a research project supervised by leading scientists at one of the participating institutions.
Course language is English. Students have access to the world largest ground- and spaced-based observatories and instrumentation operated by the participating institutes as well as to supercomputers for advanced numerical simulations and theoretical studies.
Applications for the PhD-program are open to students from all countries. Successful applicants will get a work contract / fellowship with a monthly income that covers the living costs. We will assist our students with all administrative matters for a smooth on-boarding. This means "Concentrate on your research -- we do the rest!"
For more details see: https://www.imprs-astro.mpg.de/
The closing date for applications for the program starting in September 2025 is November 1, 2024. If for any reason you have difficulty meeting the deadline, please inform us in advance and we will extend it upon request.
Forwarded from انجمن فیزیک ایران
✅ مدال دیراک سال 2024 برای فهم آنتروپی کوانتومی
#اخبار_علمی_و_پژوهشی
مدالِ دیراک سال 2024 به فیزیکدانانی رسید که در فهم آنتروپی کوانتومی در نظریه های گرانش کوانتومی و نظریه های میدان سهم داشته اند. (در تصویر فوق از چپ به راست) هوراسیو کاسینی Horacio Casini و مارینا هویرتا Marina Huerta از شورای علمی، فنی و مرکز اتمی باریلوکه آرژانتین، شینسِی رو Shinsei Ryu از ...
📣 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=4101
⏪ وبگاه انجمن فیزیک ایران:
🌍 http://www.psi.ir
✅ به کانال خبرى انجمن فیزیک ايران بپيوندید:
👇👇🏽👇👇🏽👇👇🏽👇
http://t.me/psinews
#اخبار_علمی_و_پژوهشی
مدالِ دیراک سال 2024 به فیزیکدانانی رسید که در فهم آنتروپی کوانتومی در نظریه های گرانش کوانتومی و نظریه های میدان سهم داشته اند. (در تصویر فوق از چپ به راست) هوراسیو کاسینی Horacio Casini و مارینا هویرتا Marina Huerta از شورای علمی، فنی و مرکز اتمی باریلوکه آرژانتین، شینسِی رو Shinsei Ryu از ...
📣 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=4101
⏪ وبگاه انجمن فیزیک ایران:
🌍 http://www.psi.ir
✅ به کانال خبرى انجمن فیزیک ايران بپيوندید:
👇👇🏽👇👇🏽👇👇🏽👇
http://t.me/psinews
t.me
مدال دیراک سال 2024 برای فهم آنتروپی کوانتومی
🇦🇺 PhD Scholarships in Observational, Computational & Theoretical Astrophysics 🇦🇺
The Centre for Astrophysics and Supercomputing (CAS) at Swinburne University of Technology in Melbourne invites applications from high-calibre students of any nationality for its PhD program. CAS is one of Australia's largest astronomy research institutes, with about 20 faculty, 20 postdoctoral researchers, and 40 PhD students. Swinburne has guaranteed access to the 10-m Keck telescopes, with our astronomers and students regularly obtaining time at the world's major optical and radio observatories. They also study gravitational wave sources with LIGO, and use OzSTAR, the next generation Australian Supercomputer for theoretical and observational astrophysics.
PhD scholarships include a tax free stipend, of approximately $33,500 AUD p.a., receive a tuition waiver, and have access to funding for travel to telescopes, international conferences, and collaborative meetings. For details about the program see the associated web links.
http://astronomy.swin.edu.au/study/PhDEoI/
The Centre for Astrophysics and Supercomputing (CAS) at Swinburne University of Technology in Melbourne invites applications from high-calibre students of any nationality for its PhD program. CAS is one of Australia's largest astronomy research institutes, with about 20 faculty, 20 postdoctoral researchers, and 40 PhD students. Swinburne has guaranteed access to the 10-m Keck telescopes, with our astronomers and students regularly obtaining time at the world's major optical and radio observatories. They also study gravitational wave sources with LIGO, and use OzSTAR, the next generation Australian Supercomputer for theoretical and observational astrophysics.
PhD scholarships include a tax free stipend, of approximately $33,500 AUD p.a., receive a tuition waiver, and have access to funding for travel to telescopes, international conferences, and collaborative meetings. For details about the program see the associated web links.
http://astronomy.swin.edu.au/study/PhDEoI/
astronomy.swin.edu.au
CAS - Expression of Interests
Centre for Astrophysics and Supercomputing
School of Particles and Accelerators
Special Seminar / Virtual Format
Date:
Sunday, Aug 11, 2024 / یکشنبه، 21 مرداد 1403
Time:
14:30 PM (Tehran time)
Speaker:
Dr. Jahed Abedi
Affiliation:
University of Stavanger
Title:
Search for echoes on the edge of quantum black holes
Title in Persian:
جستجو برای پژواکها در لبه سیاهچالههای کوانتومی
Abstract:
I perform a template-based search for stimulated emission of Hawking radiation (or Boltzmann echoes) by combining the gravitational wave data from 47 binary black hole merger events observed by the LIGO/Virgo collaboration. With a Bayesian inference approach, I found no statistically significant evidence for this signal in either of the 3 Gravitational Wave Transient Catalogs GWTC-1, GWTC-2 and GWTC-3. However, the data cannot yet conclusively rule out the presence of Boltzmann echoes either, with the Bayesian evidence ranging within 0.3-1.6 for most events, and a common (non-vanishing) echo amplitude for all mergers being disfavoured at only 2:5 odds. The only exception is GW190521, the most massive and confidently detected event ever observed, which shows a positive evidence of 9.2 for stimulated Hawking radiation. The ''look-elsewhere'' effect for this outlier event is assessed by applying two distinct methods to add simulated signals in real data, before and after the event, giving false (true) positive detection probabilities for higher Bayes factors of 1.5%, 4.4% (35 ± 7 %, 35 ± 15 %). An optimal combination of posteriors yields an upper limit of A < 0.4 (at 90% confidence level) for a universal echo amplitude, whereas A ~1 was predicted in the canonical model. To ensure the robustness of the results, I have employed an additional method to combine the events hierarchically. This approach involves using a target gaussian distribution and extracting the parameters from multiple uncertain observations, which may be affected by selection biases. The next generation of gravitational wave detectors such as LISA, Einstein Telescope, and Cosmic Explorer can draw a better conclusion on the quantum nature of black hole horizons.
Link to Join Virtually: https://www.skyroom.online/ch/ipm-particles/seminar
Special Seminar / Virtual Format
Date:
Sunday, Aug 11, 2024 / یکشنبه، 21 مرداد 1403
Time:
14:30 PM (Tehran time)
Speaker:
Dr. Jahed Abedi
Affiliation:
University of Stavanger
Title:
Search for echoes on the edge of quantum black holes
Title in Persian:
جستجو برای پژواکها در لبه سیاهچالههای کوانتومی
Abstract:
I perform a template-based search for stimulated emission of Hawking radiation (or Boltzmann echoes) by combining the gravitational wave data from 47 binary black hole merger events observed by the LIGO/Virgo collaboration. With a Bayesian inference approach, I found no statistically significant evidence for this signal in either of the 3 Gravitational Wave Transient Catalogs GWTC-1, GWTC-2 and GWTC-3. However, the data cannot yet conclusively rule out the presence of Boltzmann echoes either, with the Bayesian evidence ranging within 0.3-1.6 for most events, and a common (non-vanishing) echo amplitude for all mergers being disfavoured at only 2:5 odds. The only exception is GW190521, the most massive and confidently detected event ever observed, which shows a positive evidence of 9.2 for stimulated Hawking radiation. The ''look-elsewhere'' effect for this outlier event is assessed by applying two distinct methods to add simulated signals in real data, before and after the event, giving false (true) positive detection probabilities for higher Bayes factors of 1.5%, 4.4% (35 ± 7 %, 35 ± 15 %). An optimal combination of posteriors yields an upper limit of A < 0.4 (at 90% confidence level) for a universal echo amplitude, whereas A ~1 was predicted in the canonical model. To ensure the robustness of the results, I have employed an additional method to combine the events hierarchically. This approach involves using a target gaussian distribution and extracting the parameters from multiple uncertain observations, which may be affected by selection biases. The next generation of gravitational wave detectors such as LISA, Einstein Telescope, and Cosmic Explorer can draw a better conclusion on the quantum nature of black hole horizons.
Link to Join Virtually: https://www.skyroom.online/ch/ipm-particles/seminar
🇦🇺 PhD Opportunities in Astronomy & Radio Astronomy Engineering at the International Centre for Radio Astronomy Research (ICRAR), Curtin University node 🇦🇺
We invite well-qualified students of any nationality to apply to the PhD program at the Curtin Institute of Radio Astronomy (CIRA), based at Curtin University in Perth, Australia. This program focuses on radio astronomy and radio astronomy engineering in support of the Square Kilometre Array (SKA). We have a wide range of potential PhD projects to choose from (nominally for three years with a possible six-month extension).
CIRA forms one half of the International Centre for Radio Astronomy Research (ICRAR), a joint venture between Curtin University and The University of Western Australia, supported by the Western Australian Government. CIRA operates the Murchison Widefield Array (MWA), the precursor to the low frequency component of the SKA, and supports a large research group spanning Galactic and extragalactic radio astronomy, pulsars, accretion physics, studies of the Epoch of Reionisation (EoR), and radio astronomy engineering research, including significant participation in developing systems (hardware and software) for the SKA. Construction of the SKA began last year and CIRA has close connections with the SKA Observatory and the Australian SKA Regional Centre. Perth has a vibrant astronomy community with astronomers from four different institutes working closely together.
Compensation and Benefits
Compensation Type
Salary
Currency
323
Stipend
$42,000.00AUD
Included Benefits
The total annual scholarship package (stipend and tuition fees) is approx. $70,000 AUD p.a. The stipend is valued at approx. $42,000 AUD p.a.
Link to Online Application
https://astronomy.curtin.edu.au/study-with-cira/projects-for-international-and-…
Publication Start Date
2024 Jul 02
Application Deadline
2024 Aug 18
We invite well-qualified students of any nationality to apply to the PhD program at the Curtin Institute of Radio Astronomy (CIRA), based at Curtin University in Perth, Australia. This program focuses on radio astronomy and radio astronomy engineering in support of the Square Kilometre Array (SKA). We have a wide range of potential PhD projects to choose from (nominally for three years with a possible six-month extension).
CIRA forms one half of the International Centre for Radio Astronomy Research (ICRAR), a joint venture between Curtin University and The University of Western Australia, supported by the Western Australian Government. CIRA operates the Murchison Widefield Array (MWA), the precursor to the low frequency component of the SKA, and supports a large research group spanning Galactic and extragalactic radio astronomy, pulsars, accretion physics, studies of the Epoch of Reionisation (EoR), and radio astronomy engineering research, including significant participation in developing systems (hardware and software) for the SKA. Construction of the SKA began last year and CIRA has close connections with the SKA Observatory and the Australian SKA Regional Centre. Perth has a vibrant astronomy community with astronomers from four different institutes working closely together.
Compensation and Benefits
Compensation Type
Salary
Currency
323
Stipend
$42,000.00AUD
Included Benefits
The total annual scholarship package (stipend and tuition fees) is approx. $70,000 AUD p.a. The stipend is valued at approx. $42,000 AUD p.a.
Link to Online Application
https://astronomy.curtin.edu.au/study-with-cira/projects-for-international-and-…
Publication Start Date
2024 Jul 02
Application Deadline
2024 Aug 18
Curtin Institute of Radio Astronomy
Projects for International and Domestic students: - Curtin Institute of Radio Astronomy
AVAILABILITY PROJECT SUPERVISOR STATUS International and Domestic Probing the First Galaxies via Neutral Hydrogen Nick Seymour APPLY HERE International and Domestic From Observation to Mitigation: Leveraging LSST, the Global Fireball Observatory, and DREAMS…
Institute for Research in Fundamental Sciences (IPM)
SoA Virtual Seminar
Impact of AGN feedback on the dynamics of gas; A Review Across Diverse Environments
Mojtaba Raouf Hajar Zarrin
(Leiden Observatory, Netherlands)
Abstract:
We examine the relationship between black hole activity and kinematic gas-star misalignment in different galaxies. In the case of brightest group galaxies (BGGs), the formation history of galaxy groups is assessed through "age-dating" as an indicator of distinct major mergers involving the BGG. BGGs within groups characterized by a higher frequency of major mergers are more likely to host active supermassive black holes (SMBHs). A consistent correlation is identified between the level of black hole activity, as indicated by the 1.4 GHz and 325 MHz radio emissions, and the degree of kinematic misalignment between the gas and stellar components in BGGs. In dynamically "fossil" groups, where black hole accretion rate is relatively (~ 1 dex) lower due to the lack of recent (≤ 1 Gyr) major mergers, there is reduced (~ 30%) misalignment between the gas and stellar components of BGGs compared to non-fossil groups. Through examining the smaller-scale properties and dynamics of the gas disc influenced by mechanical AGN feedback, hydrodynamic simulations (HDGAS) suggest that AGN wind-induced effects further lead to persistent gas misalignment of the disk around the supermassive black hole, independent of environmental impacts.
سه شنبه 23 ماه امرداد 1403 ساعت 13:30
Tuesday 13 August 2024-Tehran Time 13:30
To join the seminar, please click on the following link
https://www.skyroom.online/ch/soa/weekly-seminar
SoA Virtual Seminar
Impact of AGN feedback on the dynamics of gas; A Review Across Diverse Environments
Mojtaba Raouf Hajar Zarrin
(Leiden Observatory, Netherlands)
Abstract:
We examine the relationship between black hole activity and kinematic gas-star misalignment in different galaxies. In the case of brightest group galaxies (BGGs), the formation history of galaxy groups is assessed through "age-dating" as an indicator of distinct major mergers involving the BGG. BGGs within groups characterized by a higher frequency of major mergers are more likely to host active supermassive black holes (SMBHs). A consistent correlation is identified between the level of black hole activity, as indicated by the 1.4 GHz and 325 MHz radio emissions, and the degree of kinematic misalignment between the gas and stellar components in BGGs. In dynamically "fossil" groups, where black hole accretion rate is relatively (~ 1 dex) lower due to the lack of recent (≤ 1 Gyr) major mergers, there is reduced (~ 30%) misalignment between the gas and stellar components of BGGs compared to non-fossil groups. Through examining the smaller-scale properties and dynamics of the gas disc influenced by mechanical AGN feedback, hydrodynamic simulations (HDGAS) suggest that AGN wind-induced effects further lead to persistent gas misalignment of the disk around the supermassive black hole, independent of environmental impacts.
سه شنبه 23 ماه امرداد 1403 ساعت 13:30
Tuesday 13 August 2024-Tehran Time 13:30
To join the seminar, please click on the following link
https://www.skyroom.online/ch/soa/weekly-seminar
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🇬🇧🇺🇸 NEW COLLEGE OXFORD - JOHNS HOPKINS CENTRE FOR COSMOLOGICAL STUDIES 🇺🇸🇬🇧
FUNDING FOR POSTDOC/POSTGRAD TRAVEL TO OXFORD, IAP AND JHU
These grants are intended to support travel by postdocs, research fellows and final year postgrads to work with a wide range of staff at Oxford, the Institut d’Astrophysique in Paris, and at Johns Hopkins in Baltimore. Travel to Paris or Baltimore can be for trips of duration ranging from 2 weeks to 2 months. Applications are welcome from anyone whose work is connected to cosmology in a very broad sense.
Visits to Oxford are intended to cover the substantial part of a term, normally 6-8 weeks, and include visiting membership of the New College Senior Common Room.
Typical awards cover flights, accommodation and a substantial contribution to living costs.
Full details can be found on the Centre’s website at https://balzan.new.ox.ac.uk/
Deadline: 23rd August 2024 (Applications require only a short research proposal.)
FUNDING FOR POSTDOC/POSTGRAD TRAVEL TO OXFORD, IAP AND JHU
These grants are intended to support travel by postdocs, research fellows and final year postgrads to work with a wide range of staff at Oxford, the Institut d’Astrophysique in Paris, and at Johns Hopkins in Baltimore. Travel to Paris or Baltimore can be for trips of duration ranging from 2 weeks to 2 months. Applications are welcome from anyone whose work is connected to cosmology in a very broad sense.
Visits to Oxford are intended to cover the substantial part of a term, normally 6-8 weeks, and include visiting membership of the New College Senior Common Room.
Typical awards cover flights, accommodation and a substantial contribution to living costs.
Full details can be found on the Centre’s website at https://balzan.new.ox.ac.uk/
Deadline: 23rd August 2024 (Applications require only a short research proposal.)
School of Physics: HEPCo Weekly Seminar Series
Speaker
Mohanna Shams
Affiliation
Institute for advanced studies in basic sciences (IASBS)
Title of talk
2D Bi-Scalar Gravity from 4D Horndeski Theory
گرانش دو-اسکالر دو-بعدی منتج شده از نظریه ی هورندسکی چهار بعدی
Date and time
Tuesday, August 13th, 2024 (Mordad 23rd, 1403), 3:00 pm (Tehran zone)
Link
https://www.skyroom.online/ch/schoolofphysics/highenergyseminar
Abstract
In this talk, I will present aspects of 2D scalar-tensor theories. First, I will construct a 2D bi-scalar gravity from a 4D Horndeski theory using a Kaluza-Klein (KK) dimensional reduction on a 2-sphere. I will then provide some identities to write the action in a more compact form and use these to develop a more generalized 2D bi-scalar theory. Following this, I will use the KK reduction process to map 4D Horndeski solutions to 2D bi-scalar theory solutions.
In the second half of the talk, I will explore the single-scalar version of the 2D bi-scalar gravity. I will discuss how some important 2D single-scalar theories may have a 4D origin. I will then investigate the relationship between some key 2D single-scalar tensor theories, explaining how the 2D Horndeski theory and GRZ model can be derived from JT gravity using disformal transformation.
Speaker
Mohanna Shams
Affiliation
Institute for advanced studies in basic sciences (IASBS)
Title of talk
2D Bi-Scalar Gravity from 4D Horndeski Theory
گرانش دو-اسکالر دو-بعدی منتج شده از نظریه ی هورندسکی چهار بعدی
Date and time
Tuesday, August 13th, 2024 (Mordad 23rd, 1403), 3:00 pm (Tehran zone)
Link
https://www.skyroom.online/ch/schoolofphysics/highenergyseminar
Abstract
In this talk, I will present aspects of 2D scalar-tensor theories. First, I will construct a 2D bi-scalar gravity from a 4D Horndeski theory using a Kaluza-Klein (KK) dimensional reduction on a 2-sphere. I will then provide some identities to write the action in a more compact form and use these to develop a more generalized 2D bi-scalar theory. Following this, I will use the KK reduction process to map 4D Horndeski solutions to 2D bi-scalar theory solutions.
In the second half of the talk, I will explore the single-scalar version of the 2D bi-scalar gravity. I will discuss how some important 2D single-scalar theories may have a 4D origin. I will then investigate the relationship between some key 2D single-scalar tensor theories, explaining how the 2D Horndeski theory and GRZ model can be derived from JT gravity using disformal transformation.
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🇮🇹 The PhD School in Physics of the Physics Department of the University of Pisa announces the opening of a PhD position in "Theoretical methods for detecting new physics signals” 🇮🇹
The duration of the PhD in Physics is 3 years. Admissions are via evaluation of the curriculum and an interview. Selected candidates receive a scholarship to cover their living expenses. PhD students attend advanced courses and participate to workshops, conferences and PhD schools. Under the guidance of a personal supervisor, PhD students learn how to carry on research at international level which leads to the writing up of a PhD thesis. The PhD programme is completed successfully after passing a final exam.
Informations about the research activity of the Theoretical Physics Department can be found at:
https://sites.google.com/a/unipi.it/pisa-theory-group/
The official announcement with instructions about how to apply and information about the available PhD positions can be found at:
https://dottorato.unipi.it/index.php/en/application-process-for-the-academic-year-2024-2025/item/874.html
https://dottorato.unipi.it/index.php/en/application-process-for-the-academic-year-2023-2024/item/766.html
and
https://dottorato.unipi.it/images/stories/competition2024_2025/concorsi_c_eng/fisica04_c_eng.pdf
A practical guide to fill the application online can be found at:
https://dottorato.unipi.it/images/stories/competition2024_2025/documents/guide40b_eng.pdf
The deadline is 22 June at 13:00 (CEST)
Contact: D'Elia, Massimo (massimo.delia@unipi.it)
The duration of the PhD in Physics is 3 years. Admissions are via evaluation of the curriculum and an interview. Selected candidates receive a scholarship to cover their living expenses. PhD students attend advanced courses and participate to workshops, conferences and PhD schools. Under the guidance of a personal supervisor, PhD students learn how to carry on research at international level which leads to the writing up of a PhD thesis. The PhD programme is completed successfully after passing a final exam.
Informations about the research activity of the Theoretical Physics Department can be found at:
https://sites.google.com/a/unipi.it/pisa-theory-group/
The official announcement with instructions about how to apply and information about the available PhD positions can be found at:
https://dottorato.unipi.it/index.php/en/application-process-for-the-academic-year-2024-2025/item/874.html
https://dottorato.unipi.it/index.php/en/application-process-for-the-academic-year-2023-2024/item/766.html
and
https://dottorato.unipi.it/images/stories/competition2024_2025/concorsi_c_eng/fisica04_c_eng.pdf
A practical guide to fill the application online can be found at:
https://dottorato.unipi.it/images/stories/competition2024_2025/documents/guide40b_eng.pdf
The deadline is 22 June at 13:00 (CEST)
Contact: D'Elia, Massimo (massimo.delia@unipi.it)
Google
Pisa Theory Group
Welcome! This is the web page of the Theoretical Physics Group at the
Physics Department, Pisa University and INFN, Pisa Division.
Here you can find information about our group members and research activity.
Physics Department, Pisa University and INFN, Pisa Division.
Here you can find information about our group members and research activity.
✳️ دانشمندان اولین مطالعه غیر خطی مربوط به شبیه ساز های سیاهچاله ها را انجام دادند ✳️
لینک گزارش
@PDATLAB
لینک گزارش
@PDATLAB
phys.org
Scientist performs the first nonlinear study of black hole mimickers
In recent research, a scientist from Princeton University has performed the first nonlinear study of the merger of a black hole mimicker, aiming to understand the nature of gravitational wave signals ...
School of Physics: HEPCo Weekly Seminar Series
Speaker
Niloofar Vardian
Affiliation
SISSA
Title of talk
Bulk Reconstruction: Explicit Entanglement Wedge Reconstruction via Petz Map
بازسازی صریح ناحیه درهمتنیدگی توسط نگاشت پتز
Date and time
Tuesday, August 20th, 2024 (Mordad 30th, 1403), 2:00 pm (Tehran zone)
Link
https://www.skyroom.online/ch/schoolofphysics/highenergyseminar
Abstract
We revisit entanglement wedge reconstruction in AdS/CFT using the Petz recovery channel. In the case of a spherical region on the boundary, we show that the Petz map reproduces the AdS-Rindler HKLL reconstruction. Moreover, for a generic subregion of the boundary, we could obtain the same boundary representation of a local bulk field lies in the entanglement wedge as the one proposed earlier in JLMS paper using properties of the modular flow.
Speaker
Niloofar Vardian
Affiliation
SISSA
Title of talk
Bulk Reconstruction: Explicit Entanglement Wedge Reconstruction via Petz Map
بازسازی صریح ناحیه درهمتنیدگی توسط نگاشت پتز
Date and time
Tuesday, August 20th, 2024 (Mordad 30th, 1403), 2:00 pm (Tehran zone)
Link
https://www.skyroom.online/ch/schoolofphysics/highenergyseminar
Abstract
We revisit entanglement wedge reconstruction in AdS/CFT using the Petz recovery channel. In the case of a spherical region on the boundary, we show that the Petz map reproduces the AdS-Rindler HKLL reconstruction. Moreover, for a generic subregion of the boundary, we could obtain the same boundary representation of a local bulk field lies in the entanglement wedge as the one proposed earlier in JLMS paper using properties of the modular flow.
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با سلام و عرض احترام،
روز شنبه ۲۷ مرداد ماه (فردا)، ساعت ۱۰-۱۲ صبح، در فضای مجازی سخنرانی و گپ و گفتی با عنوان «زنان تاثیرگذار در فیزیک ذرات» خواهیم داشت. طبعا سخنرانی را با یادی از خانواده کوری ها آغاز خواهیم کرد. سپس یادی از امی نوتر خواهیم نمود. از ماریا گوپرت مایر یاد کرده، به آزمایش «وو» خواهیم پرداخت. با توجه به این که هفته گذشته، تی-دی-لی جان به جان آفرین تسلیم کرد، به سهم ایشان به همراه سی-ان-ینگ در کشف نقض پاریته نیزاشاره خواهیم کرد. سپس به میلا بالدو و دستاوردهای علمی او و نیز دستاوردهای همنسلان او برای حقوق زنان خواهیم پرداخت.
در خلال بحث ها، به نکات و کلیشه هایی خواهیم پرداخت که زنان و مردان در جامعه دانشگاهی ایران-به خصوص در جامعه فیزیک ایران- با آنها درگیرند. امیدواریم با ایجاد هشیاری در این زمینه زنان و مردان جوان را که قدم در راه مسیر طولانی کارهای پژوهشی نهاده اند از درگیر شدن با حاشیه های بی ثمر باز داریم.
از کلیه خانم ها و آقای علاقه مند به این گونه بحث ها دعوت می نمایم که در این جلسه شرکت کنند. پوستر برنامه در پیوست موجود است.
لینک شرکت در برنامه:
https://www.skyroom.online/ch/schoolofphysics/colloquium
به امید دیدار
یاسمن فرزان
روز شنبه ۲۷ مرداد ماه (فردا)، ساعت ۱۰-۱۲ صبح، در فضای مجازی سخنرانی و گپ و گفتی با عنوان «زنان تاثیرگذار در فیزیک ذرات» خواهیم داشت. طبعا سخنرانی را با یادی از خانواده کوری ها آغاز خواهیم کرد. سپس یادی از امی نوتر خواهیم نمود. از ماریا گوپرت مایر یاد کرده، به آزمایش «وو» خواهیم پرداخت. با توجه به این که هفته گذشته، تی-دی-لی جان به جان آفرین تسلیم کرد، به سهم ایشان به همراه سی-ان-ینگ در کشف نقض پاریته نیزاشاره خواهیم کرد. سپس به میلا بالدو و دستاوردهای علمی او و نیز دستاوردهای همنسلان او برای حقوق زنان خواهیم پرداخت.
در خلال بحث ها، به نکات و کلیشه هایی خواهیم پرداخت که زنان و مردان در جامعه دانشگاهی ایران-به خصوص در جامعه فیزیک ایران- با آنها درگیرند. امیدواریم با ایجاد هشیاری در این زمینه زنان و مردان جوان را که قدم در راه مسیر طولانی کارهای پژوهشی نهاده اند از درگیر شدن با حاشیه های بی ثمر باز داریم.
از کلیه خانم ها و آقای علاقه مند به این گونه بحث ها دعوت می نمایم که در این جلسه شرکت کنند. پوستر برنامه در پیوست موجود است.
لینک شرکت در برنامه:
https://www.skyroom.online/ch/schoolofphysics/colloquium
به امید دیدار
یاسمن فرزان
www.skyroom.online
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