Another Gravitational Explanation Of Dark Matter And Dark Energy Phenomena

Another interesting gravitational explanation of dark matter and dark energy phenomena.

We argue that the effect of cold dark matter in the cosmological setup can be explained by the coupling between the baryonic matter particles in terms of the long-range force having a graviton mass mg via the Yukawa gravitational potential. Such a quantum-corrected Yukawa-like gravitational potential is characterized by the coupling parameter α, the wavelength parameter λ, which is related to the graviton mass via m(g)=ℏ/(λc), that determines the range of the force and, finally, a Planck length quantity l(0) that makes the potential regular at the centre. The corrected Friedmann equations are obtained using Verlinde's entropic force interpretation of gravity based on the holographic scenario and the equipartition law of energy. The parameter α modifies Newton's constant as G(eff)→G(1+α). We argue that dark matter is an apparent effect as no dark matter particle exists in this picture. Furthermore, the dark energy is also related to graviton mass and α; in particular, we point out that the cosmological constant can be viewed as a self-interaction effect between gravitons. We further show that there exists a precise correspondence with Verlinde's emergent gravity theory, and due to the long-range force, the theory can be viewed as a non-local gravity theory. To this end, we performed the phase space analyses and estimated λ≃103[Mpc] and α∈(0.0385,0.0450), respectively. Finally, from these values, for the graviton mass, we get mg≃10^−68 kg, and cosmological constant Λ≃10^−52m^−2. Further, we argue how this theory reproduces the MOND phenomenology on galactic scales via the acceleration of Milgrom a(0)≃10^−10m/s^2.

Kimet Jusufi, Genly Leon, Alfredo D. Millano, "Dark Universe Phenomenology from Yukawa Potential?" arXiv:2304.11492 (May 14, 2024) (Phys. Dark Univ. 42 (2023), 101318).

Tunisian Arabic v. Maltese

The Tunisian dialect of the Arabic language is basically the same as the Maltese language, except that Tunisian is written in Arabic script, while Maltese is written in the Latin alphabet.

A Notable Modified Gravity Paper And The Running Of Gravitational Couplings

It is unclear to me why gravitational mass should differ from gravitational mass-energy for this purpose. Massless particles gravitate if they have energy.

Some time ago, it has been suggested that gravitons can acquire mass in the process of spontaneous symmetry breaking of diffeomorphisms through the condensation of scalar fields [Chamseddine and Mukhanov, JHEP, 2010]. Taking this possibility into account, in the present paper, first we show how the graviton mass intricately reshapes the gravitational potential akin to a Yukawa-like potential at large distances. Notably, this long-range force modifies the Newton's law in large distances and might explain the phenomena of dark matter. The most important finding in the present paper is the derivation of a modified Newtons law of gravity by modifying the Verlindes entropic force relation due to the graviton contribution. The graviton contribution to the entropy basically measures the correlation of graviton and matter fields which then reproduces the Bekenstein-Hawking entropy at the horizon. This result shows the dual description of gravity: in the language of quantum information and entropy the gravity can be viewed as an entropic force, however in terms of particles and fields, it can be viewed as a longe range force. Further we have recovered the corrected Einstein field equations as well as the ΛCDM where dark matter emerges as an apparent effect.

Kimet Jusufi, et al., "Modified gravity/entropic gravity correspondence due to graviton mass" arXiv:2405.05269 (April 25, 2024).

There is also a preprint on the beta function of gravity in a quantum gravity scenario that is particularly relevant globally to the running of Standard Model constants at extremely high energies and the cosmology of the immediate post-Big Bang period and in strong gravitational regimes.

We study the beta functions for the dimensionless couplings in quadratic curvature gravity, and find that there is a simple argument to restrict the possible form of the beta functions as derived from the counterterms at an arbitrary loop. The relation to the recent different results on beta functions is also commented on.

Hikaru Kawai, Nobuyoshi Ohta, "An Observation on the Beta Functions in Quadratic Gravity" arXiv:2405.05706 (May 9, 2024).

Connecting Denisovan DNA To Bones

A new study looks at what Denisovan ancient DNA codes for in order to determine which hominin remains that have been located are the best fit to that DNA. These remains would have been contemporaneous with the earliest modern humans and with Neanderthals.

The Dali and Harbin specimens that are a good fit to the expectation from the Denisovan DNA samples are from China. 

Dali Man was discovered in 1978 in Dali County, Shaanxi Province, China and dates to 280,000 to 240,000 years ago. 

The Harbin specimen was recovered in Harbin city in northeastern China and has a minimum uranium-series age of 146,000 year ago.

The Kabwe specimen, also known as the "Broken Hill skull" and "Rhodesian Man", which is also a good fit to Denisovan DNA expectations, was discovered in 1921 in Zambia, which is outside the range of places where Denisovan admixture is found in modern humans. It has traditionally been classified as Homo heidelbergensis, a species which is widely hypothesized to be a lineage ancestral to Denisovans, Neanderthals, and modern humans. This specimen is dated to 324,000 to 274,000 years ago.

Denisovans are an extinct group of humans whose morphology is mostly unknown. The scarcity of verified Denisovan fossils makes it challenging to study how they differed in their anatomy, and how well they were adapted to their environment. To gain insight into their evolutionary history, we used a genetic phenotyping approach, where Denisovan anatomy was inferred by detecting gene regulatory changes that likely altered Denisovan skeletal morphology. 

We then scanned Middle Pleistocene skulls for unclassified specimens that match our Denisovan profile and thus might have been related to Denisovans. We found that the Harbin, Dali, and Kabwe specimens show a particularly good match to the predicted Denisovan profile. We conclude that our genetic phenotyping approach could help classify unidentified specimens, and that Harbin, Dali, and Kabwe likely belonged to individuals closely linked to the Denisovan lineage.

Nadav Mishol, et al., "Candidate Denisovan fossils identified through gene regulatory phenotyping" bioRxiv (April 19, 2024) (emphasis and links in the abstract added editorially).

The First Farmers Of Cyprus Were Mostly Anatolian

Neolithic Cyprus was settled from Turkey, not Greece, by a sister population to the first farmers of Europe, very early in the Fertile Crescent derived Neolithic era. 

Archaeological evidence supports sporadic seafaring visits to the Eastern Mediterranean island of Cyprus by Epipaleolithic hunter-gatherers over 12,000 years ago, followed by permanent settlements during the early Neolithic. The geographical origins of these early seafarers have so far remained elusive. 

By systematically analysing all available genomes from the late Pleistocene to early Holocene Near East (c. 14,000–7000 cal BCE), we provide a comprehensive overview of the genetic landscape of the early Neolithic Fertile Crescent and Anatolia and infer the likely origins of three recently published genomes from Kissonerga-Mylouthkia (Cypriot Late Pre-Pottery Neolithic B, c. 7600–6800 cal BCE). These appear to derive roughly 80% of their ancestry from Aceramic Neolithic Central Anatolians residing in or near the Konya plain, and the remainder from a genetically basal Levantine population. 

Based on genome-wide weighted ancestry covariance analysis, we infer that this admixture event took place roughly between 14,000 and 10,000 BCE, coinciding with the transition from the Cypriot late Epipaleolithic to the Pre-Pottery Neolithic A (PPNA). Additionally, we identify strong genetic affinities between the examined Cypro-LPPNB individuals and later northwestern Anatolians and the earliest European Neolithic farmers. 

Our results inform archaeological evidence on prehistoric demographic processes in the Eastern Mediterranean, providing important insights into early seafaring, maritime connections, and insular settlement.

Alexandros Heraclides, et al., "Palaeogenomic insights into the origins of early settlers on the island of Cyprus" 14 Scientific Reports 9632 (April 26, 2024) (open access).

Some comments about early pottery

Pottery appears to have been an East Asian innovation, that arose prior to farming and herding in sedentary fishing based communities like the Jomon and people with similar lifestyles in what is now China and Korea, that gradually migrated to the West across North Asia, mostly arriving in West Asia and Europe after herding and farming had been developed there.

Also, it is worth noting that Western anthropologists use the term "Neolithic" to refer to the commencement of widespread use of domesticated plants and animals, while Soviet and post-Soviet anthropologists use the term "Neolithic" to refer to the commencement of widespread use of pottery.

A Neutrino Mass Puzzle

The differences between the three neutrino masses is known to considerable precision and is most easily communicated in meV units. But the absolutely masses are not very meaningfully constrained from direct measurements of the neutrino masses. Cosmology based constraints on the sum of the three neutrino masses are much more restrictive. 

But a new preprint based upon newly released DESI data shows that we are at the brink of being over constrained, as the sum of the three neutrino masses estimated from cosmology is likely to fall below the minimum sum of the three neutrino masses from neutrino oscillation data. 

This suggests that the cosmology based bounds may be unreliable. This isn't all that stunning given that myriad problems with the LambdaCDM model, even though the sum of the neutrino masses estimates from cosmology are quite robust over a wide range of assumptions.

On the other hand, cosmology based bounds aren't the only factors that favor a normal neutrino mass hierarchy over an inverted neutrino mass hierarchy. A normal neutrino mass hierarchy leaves two possibilities: either a near minimal sum of the three neutrino masses, independent of cosmology considerations, or a nearly degenerate set of neutrino masses, as the main possibilities. The large size of the PMNS matrix mixing angles relative to those in the CKM matrix for quarks suggests that the hierarchy of neutrino masses may indeed be less steep than that of the quarks. But there is no established theory to quantify that intuition.

The baryon acoustic oscillation (BAO) analysis from the first year of data from the Dark Energy Spectroscopic Instrument (DESI), when combined with data from the cosmic microwave background (CMB), has placed an upper-limit on the sum of neutrino masses, ∑mν<70 meV (95%). In addition to excluding the minimum sum associated with the inverted hierarchy, the posterior is peaked at ∑mν=0 and is close to excluding even the minimum sum, 58 meV at 2σ. 

In this paper, we explore the implications of this data for cosmology and particle physics. The sum of neutrino mass is determined in cosmology from the suppression of clustering in the late universe. 

Allowing the clustering to be enhanced, we extended the DESI analysis to ∑mν<0 and find ∑mν=−160±90 meV (68%), and that the suppression of power from the minimum sum of neutrino masses is excluded at 99% confidence. 

We show this preference for negative masses makes it challenging to explain the result by a shift of cosmic parameters, such as the optical depth or matter density. 

We then show how a result of ∑mν=0 could arise from new physics in the neutrino sector, including decay, cooling, and/or time-dependent masses. These models are consistent with current observations but imply new physics that is accessible in a wide range of experiments. 

In addition, we discuss how an apparent signal with ∑mν<0 can arise from new long range forces in the dark sector or from a primordial trispectrum that resembles the signal of CMB lensing.

Nathaniel Craig, Daniel Green, Joel Meyers, Surjeet Rajendran, "No νs is Good News" arXiv:2405.00836 (May 1, 2024).

Another preprint today greatly loosens the bound on the muon neutrino mass from more direct measurements to about 150 keV, which is a huge step backwards from the previous direct detection bound of 420 eV proposed in the year 2014.

The tightest bound on the lightest neutrino mass eigenstate is about 0.8 eV (and is likely to drop to 0.2 eV as experimental methods improve). Combining the current bound and the mass differences permitted from neutrino oscillation data keeps all three neutrino mass eigenstates at under 1 eV in either a normal or an inverted neutrino mass hierarchy (and the sum of the three neutrino masses under 2.6 eV). So the neutrino mass bounds from the new preprint and from the 2014 study are meaningless.

If the lightest neutrino mass were constrained to be 0.2 eV or less, the sum of the three neutrino masses in either hierarchy, could be constrained to be no more than about 0.71 eV (0.66 eV in a normal hierarchy), which while not competitive with the potentially discredited cosmology bounds, would still be far less of a setback.

The background from the muon neutrino mass preprint states the following:

As a result of the discovery of neutrino flavor oscillations, neutrinos are thought to have a non-zero mass, as opposed to the standard model (SM). The detection of neutrino oscillations in the atmospheric Super-Kamiokande and solar Sudbury Neutrino Observatory (SNO) experiments provided initial evidence supporting the existence of nonzero neutrino masses. In the 21st century, several neutrino oscillation experiments were conducted, providing precise measurements for the phenomenon of neutrino oscillation. However, these experiments revealed that two out of the three flavors are heavy, and the massive flavor possesses a mass of at least 0.05 eV. Nonetheless, it should be noted that these experiments could only determine mass-squared differences between the flavors and were unable to directly measure the individual mass of each flavor. 

It is crucial to highlight that the theoretical concept of neutrino oscillation was initially proposed by the Russian scientist Bruno Pontecorvo to elucidate the absence of detected atmospheric and solar neutrinos. 

Measuring neutrino mass is of a great importance due to its implications regarding not only refining our understanding about the nature of the universe and dark matter, but also conceivably providing insights into some new physics beyond SM. Therefore, one of the main objectives of particle physicists has been to measure neutrino masses for several years. Consequently, numerous experiments have been conducted since 1991 to measure the mass of neutrinos based on tritium beta decay, from Los Alamos to the Karlsruhe Tritium Neutrino experiment in 2022. 

At Los Alamos, researchers established an upper limit of 11 eV at a 95% confidence level for the mass of the electron anti-neutrino, m(¯ νe). In the first run in 2019, the KATRIN experiment significantly improved the sensitivity of m(¯ νe), setting a new upper bound of 1.1 eV at 90% confidence level (CL), which represents an improvement by a factor of about two compared to the previous limit. Furthermore, in the second run in 2022, they achieved a more precise upper bound of 0.9 eV at 90% CL. The results from the KATRIN 2019 (first run) were then combined with those from KATRIN 2022 (second run), resulting in a more accurate upper limit of 0.8 eV at a 90% CL for m(¯ νe). 

On the other hand, the most successful attempts to measure the mass of muon neutrinos, as the second flavor, were in 1982, involving the measurement of muon neutrinos from pion decay in flight and achieving an upper bound of less than 500 keV, and in 1996, measuring muon neutrinos from the decay of pions at rest, resulting in an upper limit of less than 170-190 keV.

A True Garbage Physics Paper

How do we create incentives in High Energy Physics to discourage such utterly garbage filled advocacy of discredited dead end speculation?

At present, the Standard Model (SM) agrees with almost all collider data. Yet, three finetuning issues -- the Higgs mass problem, the strong CP problem and the cosmological constant problem -- all call for new physics. The most plausible solutions at present are weak scale SUSY, the PQWW axion and the string landscape. A re-evaluation of EW finetuning in SUSY allows for a higgsino-like LSP and naturalness upper bounds well beyond LHC limits. Rather general arguments from string theory allow for statistical predictions that m_h~ 125 GeV with sparticles beyond present LHC limits. The most lucrative LHC search channel may be for light higgsino pair production. Dark matter turns out to be a SUSY DFSZ axion along with a diminished abundance of higgsino-like WIMPs.

Howard Baer, "Beyond the Standard Model: An overview" arXiv:2405.00872 (May 1, 2024) (contribution to the 2024 QCD session of the 58th Rencontres de Moriond).

Japan's Sun God

I saw a reference to the story of Amaterasu being lured out of her cave and looked up the story. 

Japan's Shinto religion is often described as animistic, rather than polytheistic, and it does have many small gods (kami). But the story of Amaterasu has strong echos of the Greek gods, with odd births and amoral gods. I had been unaware that the story including siblings having children together, a moderately unusual theme in legends. As the reference below notes, it is also one of the only religions with a female sun god and a male moon god.

Of course, the existing Japanese royal family is one of the oldest still extant royal dynasties on Earth, and the only one of which I am aware that claims divine ancestry.

Amaterasu, (Japanese: “Great Divinity Illuminating Heaven”), the celestial sun goddess from whom the Japanese imperial family claims descent, and an important Shintō deity. 

She was born from the left eye of her father, Izanagi, who bestowed upon her a necklace of jewels and placed her in charge of Takamagahara (“High Celestial Plain”), the abode of all the kami. 

One of her brothers, the storm god Susanoo, was sent to rule the sea plain. Before going, Susanoo went to take leave of his sister. As an act of good faith, they produced children together, she by chewing and spitting out pieces of the sword he gave her, and he by doing the same with her jewels. Susanoo then began to behave very rudely—he broke down the divisions in the rice fields, defiled his sister’s dwelling place, and finally threw a flayed horse into her weaving hall. Indignant, Amaterasu withdrew in protest into a cave, and darkness fell upon the world.

The other 800 myriads of gods conferred on how to lure the sun goddess out. They collected cocks, whose crowing precedes the dawn, and hung a mirror and jewels on a sakaki tree in front of the cave. The goddess Amenouzume (q.v.) began a dance on an upturned tub, partially disrobing herself, which so delighted the assembled gods that they roared with laughter. Amaterasu became curious how the gods could make merry while the world was plunged into darkness and was told that outside the cave there was a deity more illustrious than she. She peeped out, saw her reflection in the mirror, heard the cocks crow, and was thus drawn out from the cave. The kami then quickly threw a shimenawa, or sacred rope of rice straw, before the entrance to prevent her return to hiding.

Amaterasu’s chief place of worship is the Grand Shrine of Ise, the foremost Shintō shrine in Japan. She is manifested there in a mirror that is one of the three Imperial Treasures of Japan (the other two being a jeweled necklace and a sword). The genders of Amaterasu and her brother the moon god Tsukiyomi no Mikato are remarkable exceptions in worldwide mythology of the sun and the moon. See also Ukemochi no Kami.

From the Encyclopedia Britannica. Simple English Wikipedia's retelling of the story is here.

Fun fact: The most energetic particle in a cosmic ray ever seen by astronomers has been named after Amaterasu.