From The International School for Advanced Studies [Scuola Internazionale Superiore di Studi Avanzati](IT) : “Revealing the secret language of dark matter”
4.29.22
Nico Pitrelli
pitrelli@sissa.it
T +39 040 3787462
M +39 339 1337950
Donato Ramani
ramani@sissa.it
T +39 040 3787513
M +39 342 80 222 37
Shedding light on the interplay of dark matter with standard matter, a new
SISSA study suggests a possible solution to one of the greatest and long-
standing mystery of astrophysics. The theory proposes a new property,
called “non-minimal coupling,” that would shed light on this mysterious
interaction. The research has been published in The AstrophysicalJournal.
In the Universe dark matter and standard matter “talk” to each other using a
secret language. This “discussion” happens thanks to gravity, scientists say but
not in a way they can fully comprehend. A new SISSA study published in The
Astrophysical Journal sheds light on this long-standing issue.
The authors of the research, Ph.D Student Giovanni Gandolfi and supervisors
Andrea Lapi and Stefano Liberati, propose a special property for dark matter
called a “non-minimal coupling with gravity”. This new type of interaction can
modify dark matter gravitational influence on standard “baryonic” matter.
According to the authors, the ‘non-minimal coupling’ could be the key to decrypt
the enigmatic dialogue between the two components, possibly solving one of the
biggest open questions about dark matter’s nature.
To prove the hypothesis, the assumption has been tested and then confirmed
with experimental data from thousands of spiral galaxies.
The mysterious interplay with standard matter
“Dark matter is everywhere” says the research’s authors. “Like a cosmic
scaffolding, it interconnects the Universe and holds galaxies together.
Dark matter is as important as mysterious, though. Possibly, one of dark matter’s
greatest enigmas is its interplay with standard matter, or ‘baryons’”. We know that
in this dialogue gravity has an important role, but scientists still don’t entirely
understand the phenomenon. “For this reason” say Gandolfi, Lapi and Liberati
“we asked ourselves: is gravity wrong or are we just missing something crucial
about dark matter’s nature? What if dark matter and standard ‘baryonic’ matter do
not communicate in the way we have always imagined?. With our research, we
have tried to answer these intriguing questions”.
The “non-minimal coupling”
The new study suggests the existence of a new feature of dark matter, named
‘non-minimal coupling’, which “can be described as a new type of interaction
between dark matter and gravity” the authors affirm. “It tells us a lot about the
way the two components “communicate”. If the non-minimal coupling is present,
standard matter “perceives” spacetime in a way which is different from the one
“experienced” by the dark matter. And this is a very interesting point. Usually, in
fact, dark matter and baryonic matter perceive spacetime in the same way. For
this reason, our theory, that we have proven to be in remarkable agreement with
present experimental data, could represent a crucial issue in understanding the
essence of dark matter”.
For a global comprehension of dark matter
The new study proposes a solution to one of the most discussed problems in
astrophysics, researchers say: “Among other things, the positions of those who
argue that dark matter does not exist, and therefore gravity must be modified, are
based on the difficulty of finding an explanation to this problem, which is one of
the last missing pieces for a global comprehension of dark matter”.
But there is more. “This feature of dark matter is not a piece of new exotic
fundamental physics” the author say. “One can explain the existence of this non-
minimal coupling with known physics alone”.
The future looks brighter…
“The future of dark matter looks brighter” the authors conclude. “Further studies
will be carried out to explore all the interesting implications of this proposed new
feature of dark matter. We wouldn’t be surprised to discover that this non-minimal
coupling could solve other unanswered questions of the Universe”.
_________________________________________
Dark Matter Background
Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM, denied the Nobel, some 30 years later, did most of the work on Dark Matter.
Fritz Zwicky.
Coma cluster via NASA/ESA Hubble, the original example of Dark Matter discovered during observations by Fritz Zwicky and confirmed 30 years later by Vera Rubin.
In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.
Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.
Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.
Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).
Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970.
Vera Rubin measuring spectra, worked on Dark Matter(Emilio Segre Visual Archives AIP SPL).
Dark Matter Research
Super Cryogenic Dark Matter Search from DOE’s SLAC National Accelerator Laboratory (US) at Stanford University (US) at SNOLAB (Vale Inco Mine, Sudbury, Canada).
LBNL LZ Dark Matter Experiment (US) xenon detector at Sanford Underground Research Facility(US) Credit: Matt Kapust.
Lamda Cold Dark Matter Accerated Expansion of The universe http scinotions.com the-cosmic-inflation-suggests-the-existence-of-parallel-universes. Credit: Alex Mittelmann.
DAMA at Gran Sasso uses sodium iodide housed in copper to hunt for dark matter LNGS-INFN.
</a Yale HAYSTAC axion dark matter experiment at Yale’s Wright Lab.
DEAP Dark Matter detector, The DEAP-3600, suspended in the SNOLAB (CA) deep in Sudbury’s Creighton Mine.
The LBNL LZ Dark Matter Experiment (US) Dark Matter project at SURF, Lead, SD, USA.
DAMA-LIBRA Dark Matter experiment at the Italian National Institute for Nuclear Physics’ (INFN’s) Gran Sasso National Laboratories (LNGS) located in the Abruzzo region of central Italy.
DARWIN Dark Matter experiment. A design study for a next-generation, multi-ton dark matter detector in Europe at The University of Zurich [Universität Zürich](CH).
PandaX II Dark Matter experiment at Jin-ping Underground Laboratory (CJPL) in Sichuan, China.
Inside the Axion Dark Matter eXperiment U Washington (US) Credit : Mark Stone U. of Washington. Axion Dark Matter Experiment.
__________________________________________
See the full article here.
five-ways-keep-your-child-safe-school-shootings
Please help promote STEM in your local schools.
The International School for Advanced Studies Scuola Internazionale Superiore di Studi Avanzati (SISSA) is an international, state-supported, post-graduate-education and research institute, located in Trieste, Italy.
SISSA is active in the fields of mathematics, physics, and neuroscience, offering both undergraduate and post-graduate courses. Each year, about 70 PhD students are admitted to SISSA based on their scientific qualifications. SISSA also runs master’s programs in the same areas, in collaboration with both Italian and other European universities.
SISSA was founded in 1978, as a part of the reconstruction following the Friuli earthquake of 1976. Although the city of Trieste itself did not suffer any damage, physicist Paolo Budinich asked and obtained from the Italian government to include in the interventions the institution of a new, post-graduate teaching and research institute, modeled on the Scuola Normale Superiore di Pisa. The school became operative with a PhD course in theoretical physics, and Budinich himself was appointed as general director. In 1986, Budinich left his position to Daniele Amati, who at the time was at the head of the theoretical division at The European Organization for Nuclear Research [La Organización Europea para la Investigación Nuclear][Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH)[CERN]. Under his leadership, SISSA expanded its teaching and research activity towards the field of neuroscience, and instituted a new interdisciplinary laboratory aiming at connecting humanities and scientific studies. From 2001 to 2004, the director was the Italian geneticist Edoardo Boncinelli, who fostered the development of the existing research areas. Other directors were appointed in the following years, which saw the strengthening of SISSA collaboration with other Italian and European universities in offering master’s degree programs in the three areas of the School (mathematics, physics and neuroscience). Physicist Stefano Ruffo served as the director from 2015 until 2021, when he was succeeded by Andrea Romanino.
Reply