Hei yliopistolainen! Seuraamalla tietotekniikkakeskusta @it.helsinki.fi pysyt jatkossa ajan tasalla yliopiston IT-asioissa ja saat nopeasti tiedon muun muassa tärkeistä tietoturvauutisista, palvelumuutoksista, uusista palveluista ja palvelukatkoista 💻 #helsinkiuni #IT #tietoturva
Are gigaparsec structures like the "Giant Arc" breaking the standard model of #cosmology?
No. We find similar patterns to be extremely common in a ΛCDM #universe, and we also show that the claimed overdensities are algorithmic artefacts.
What's more, these shapes detected in extremely sparse samples of galaxies are just as easily found in random point patterrns, suggesting they're spurious and don't reflect any underlying structures.
Recent discoveries of apparent large-scale features in the structure of the universe, extending over many hundreds of megaparsecs, have been claimed to contradict the large-scale isotropy and homogeneity foundational to the standard ($Λ$CDM) cosmological model. We explicitly test and refute this conjecture using FLAMINGO-10K, a new and very large cosmological simulation of the growth of structure in a $Λ$CDM context. Applying the same methods used in the observations, we show that patterns like the "Giant Arc", supposedly in tension with the standard model, are, in fact, common and expected in a $Λ$CDM universe. We also show that their reported significant overdensities are an algorithmic artefact and unlikely to reflect any underlying structure.
Nyt jännään, tiedottaako yliopisto asiasta julkisesti. Uutisoidaanko tätä? Oikeastaan toivon että ei. Päätös oli oikea, mutta tyylipisteitä saa tässä vaiheessa enää lähinnä vaikenemalla.
Sisäisen Flamma-tiedotteen kommenteissa on riehunut (vain) kaksi trollia, ilmeisesti ihan oikeilla toimihenkilönimillään. (Ehkä toinen jo tajusi trollaavansa ja ettei oikeastaan tarkoittanut trollata?) Viestintätyyppien vastaukset ovat hyviä ja osoittavat ammattitaitoa. Tämä ilahduttaa.
Mudbrick constructions are extremely common in ancient western Asia, including the 1st millennium structures of the southern Caucasus and Armenian highlands. However, in the Caucasus the geoarchaeological study of these materials to provide insight into building practices and social structure is a topic little researched, especially when focusing on the longue durée. Artashat/Artaxata (Ararat region, Armenia) was the capital of the Armenian Kingdom of the Artaxiads, founded in the eighties of the 2nd century BC, but even before this the site was occupied in the Chalcolithic period, (ca. 5200–3500 BC), Early Iron Age (ca. 1200–900 BC) and in the Urartian period (ca. 800–600 BC) as well. All the previous occupation phases showed communities that made extensive use of earthen constructions as determined during past and recent archaeological excavations. This multidisciplinary study seeks to examine mudbrick architecture as a proxy for environmental and social interactions during the 1st millennium BC combining geoarchaeology, archaeobotany and building archaeology. We analyzed changes and continuities in architectural form and practices, alongside reconstruction of technological and social processes, to identify issues of raw material procurement, attestation of re-use, and consistency of building practices. The results of the geoarchaeological analysis of the earthen building materials used in different parts of the ancient city point to a re-use of materials over time.
A nasal spray is extremely effective in preventing the disease caused by all known variants of the SARS-CoV-2 virus https://innovationtoronto.com/2023/03/a-nasal-spray-is-extremely-effective-in-preventing-the-disease-caused-by-all-known-variants-of-the-sars-cov-2-virus/
Our paper about the role of little weird objects called 't Hooft-Polyakov monopoles during early universe phase transitions was published: https://link.springer.com/article/10.1007/JHEP02(2023)212
Normally when you do Monte Carlo simulations of quantum field theories near phase transitions or in strongly coupled regimes, you get something rather different from the perturbative pen-and-paper-style calculation. But here, we found that the density of monopoles tracks the semiclassical result in this theory throughout the transition. Why, we don't really know.
The picture (by Riikka Seppä) shows a snapshot of a 'cooled' simulation configuration with the monopoles in red and blue.
We study the crossover phase transition of the SU(2) Georgi-Glashow model in three dimensions. In this model, a confining condensate of topological ’t Hooft-Polyakov monopoles exists in the Higgs regime. We use lattice Monte Carlo simulations to study the monopole gas across a crossover transition, and demonstrate that gradient flow can be used to renormalize the otherwise divergent monopole number density. The condensation of the monopoles means that the theory admits also a massive photon-like excitation. We show that the renormalized monopole number density is approximately proportional to the square of the photon mass, in agreement with semiclassical results. Our results give insight into behaviour of the Higgs regime near crossover, which has boarder implications for beyond the Standard Model theories containing adjoint scalar fields.
Saamen lippu salkoon Helsingin yliopistossa Kumpulan kampuksella Saamelaisten kansallispäivän kunniaksi.
The Sámi flag raised at the University of Helsinki on Kumpula campus in honour of 6th of February, Sámi National Day.
https://en.wikipedia.org/wiki/S%C3%A1mi_National_Day
#Helsinginyliopisto #HelsinkiUni #Saamelaistenkansallispäivä #SámiNationalDay #Sámi
I'm David, a queer Finnish physicist originally from Scotland. I write on here in a personal capacity.
I use big computers to simulate the very early universe.
I also want to become a better teacher. For example, I want to understand what leads people from minoritised groups to abandon studies in physics.
I help out with the local LGBTQ+ community, such as our LGBTQ+ STEM day events.
#Introduction #HelsinkiUni #Astrodon #Cosmology #Physics #Pedagogy #LGBTQInSTEM #QueerInSTEM #ScienceMastodon
Yliopistobotti
Till Sawala
FzB♭ 💨
Marta Lorenzon
Uncharted Territories
David Weir 
Markku Michael Jeltsch