Another Notable Effort To Explain Dark Matter And Dark Energy Phenomena With Gravity Alone

This approach is similar to Deur's approach.

[Submitted on 17 May 2018]

Nonlinear Effects of Gravity in Cosmology

Johan Hansson, Jaime Dols Duxans, Martin Svensson

We consider some nonlinear effects of gravity in cosmology. Possible physically interesting consequences include: non-requirement of dark matter and dark energy, asymmetric gravitational matter-creation, emergent homogeneity/isotropy & asymptotic flatness, resolution of "cosmic coincidence" Omega_m \sim Omega_lambda, effective cutoff of gravitational interaction at the scale of cosmic voids.

Comments:	13 pages, 2 figures
Subjects:	General Physics (physics.gen-ph)
Journal reference:	Advanced Studies in Theoretical Physics, Vol. 12, 2018, no. 4, 157 - 172
DOI:	10.12988/astp.2018.71047
Cite as:	arXiv:1805.11043 [physics.gen-ph]
	(or arXiv:1805.11043v1 [physics.gen-ph] for this version)

Explaining The Genetic Fitness Advantage Of LP and EDAR and Skin Color

In West Eurasia, the strongest target of genetic selective fitness adaptation is lactase persistence (LP) (see also here) which allows adults to drink milk, which surged around the time that Indo-Europeans migrated en masse across Europe in the late Neolithic era and early Bronze Age (often were more herding based food production than the first wave Neolithic populations of Europe derived from Anatolian farmers), and with sometimes regionally distinct genes that have the same effect, upon the arrival of pastoralism in the Near East and Africa.

In East Eurasia and the Americas, the EDAR gene which is responsible for much of the distinctively "East Asian" phenotype is a similarly powerful selective fitness adaptation in the Upper Paleolithic era (roughly speaking, after humans expanded out of Africa and before agriculture was developed). What specifically does it do?

A derived G-allele point mutation (SNP) with pleiotropic effects in EDAR, 370A or rs3827760, found in most modern East Asians and Native Americans but not common in African or European populations, is thought to be one of the key genes responsible for a number of differences between these populations, including the thicker hair, more numerous sweat glands, smaller breasts, and the Sinodont dentition (so-called shovel incisors) characteristic of East Asians. This mutation is also implicated in ear morphology differences and reduced chin protrusion. 

The mutation arose in humans approximately 30,000 years ago, and now is found in 93% of Han Chinese and in the majority of people in nearby Asian populations. 

It has been hypothesized that natural selection favored this allele during the last ice age in a population of people living in isolation in Beringia, as it may play a role in the synthesis of breast milk under Vitamin D-poor conditions. 

Previous research has shown that both LP and EDAR genes may make it easier for mothers to get Vitamin D and/or to pass Vitamin D to their children during pregnancy and in breast feeding. 

But, what is so great about mothers having high levels of Vitamin D and passing it on to their children?

Well, it turns out that the presence of Vitamin D in a mother during pregnancy enhances the IQ of her children, which has great potential to be fitness enhancing, on top of benefits like preventing miscarriage, enhancing fertility, and having immune system enhancing properties.

The importance of Vitamin D could also explain apparent selective fitness effects of matching skin color appropriately to latitude, i.e. favoring pale skin at high latitudes to enhance Vitamin D levels, while favoring darker skin at lower latitudes where solar exposure is more intense to prevent sun burns and skin cancer where it is possible to get sufficient Vitamin D even with darker skin.

The paper and its abstract are as follows:

Background

Vitamin D is critical to embryonic neuronal differentiation and other developmental processes that may affect future neurocognitive function. However, observational studies have found inconsistent associations between gestational vitamin D and neurocognitive outcomes. 

Objectives

We examined the association of gestational 25-hydroxyvitamin D [25(OH)D] with children's IQ at 4–6 y, and explored whether associations differed by race. 

Methods

This study used data from the CANDLE (Conditions Affecting Neurocognitive Development and Learning in Early Childhood) cohort. Between 2006 and 2011, CANDLE recruited 1503 women in their second trimester of healthy singleton pregnancies. Inclusion criteria for this analysis were gestation of ≥34 wk and availability of 25(OH)D and IQ data. Associations between second-trimester 25(OH)D plasma concentration and Stanford-Binet IQ scores in offspring at 4–6 y were examined using multivariable linear regression; interaction terms were used to explore possible effect modification by race. 

Results

Mean ± SD 25(OH)D concentration among 1019 eligible dyads was 21.6 ± 8.4 ng/mL, measured at a mean ± SD gestational age of 23.0 ± 3.0 wk. Vitamin D deficiency [25(OH)D < 20 ng/mL] was observed in 45.6%. Maternal 25(OH)D differed by race with a mean ± SD of 19.8 ± 7.2 ng/mL in Blacks sand 25.9 ± 9.3 ng/mL in Whites ( P < 0.001). In adjusted models a 10-ng/mL increase in 25(OH)D was associated with a 1.17-point higher Full Scale IQ (95% CI: 0.27, 2.06 points), a 1.17-point higher Verbal IQ (95% CI: 0.19, 2.15 points), and a 1.03-point higher Nonverbal IQ (95% CI: 0.10, 1.95 points). We observed no evidence of effect modification by race. 

Conclusions

Second-trimester maternal 25(OH)D was positively associated with IQ at 4–6 y, suggesting that gestational vitamin D status may be an important predictor of neurocognitive development. These findings may help inform prenatal nutrition recommendations and may be especially relevant for Black and other dark-skinned women at high risk of vitamin D deficiency.

Melissa M Melough, et al., "Maternal Plasma 25-Hydroxyvitamin D during Gestation Is Positively Associated with Neurocognitive Development in Offspring at Age 4–6 Years." The Journal of Nutrition (2020). DOI: 10.1093/jn/nxaa309

The Origins Of The Loan Words In The Romani Language

The ethnic  minority of people who now live in Europe, commonly known as the Gypsies, but more respectfully called the Romani people, have languages including a language often called the Romani language, which are part of the Indo-Aryan language family. 

The Indo-Aryan languages are a family of languages within the Indo-European language family that are ultimately derived from Sanskrit, most of which are spoken in Northern India, in Bangladesh, and in Pakistan. The most widely spoken member of the Indo-Aryan language family is Hindi (which when spoken in a Pakistani dialect and written in an Arabic script is called Urdu). 

Genetic evidence as well as linguistic and cultural evidence confirm the Northern Indian roots of the Romani people (with a migration to Europe commencing probably around 1000 CE plus or minus a century or two).

The Romani language contains a great many loan words (about 62% of its vocabulary).

About 84% of the loan word are from Hungarian (a Uralic language that is part of the same language family as the Finnish and Estonian languages and is not an Indo-European language), about 9% of the loan words are Slavic in origin (a different branch of the Indo-European language family), about 3% of the loanwords are Greek (a different branch of the Indo-European language family), about 2% of the loan words are Persian (a part of the Indo-Iranian branch of the Indo-European language family that also includes the Indo-Aryan languages), and about 3% of the loan word have other sources (the total does not add to 100% due to rounding errors). 

None of the loan words in the Romani language come from any Semitic language or from any other Afro-Asiatic language.

More background here.

Strong Observational Evidence Supports The Existence Of the External Field Effect

This September 2020 paper accepted for publication in a peer reviewed journal makes a strong empirical case that the external field effect predicted by MOND is real and that the strong equivalence principle of general relativity is violated.

Testing the Strong Equivalence Principle: Detection of the External Field Effect in Rotationally Supported Galaxies

• Chae, Kyu-Hyun; 
• Lelli, Federico; 
• Desmond, Harry;
• McGaugh, Stacy S.;
 
• Li, Pengfei;
 
• Schombert, James M.

Abstract

The Strong Equivalence Principle (SEP) distinguishes General Relativity from other viable theories of gravity. The SEP demands that the internal dynamics of a self-gravitating system under free-fall in an external gravitational field should not depend on the external field strength. We test the SEP by investigating the external field effect (EFE) in Milgromian dynamics (MOND), proposed as an alternative to dark matter in interpreting galactic kinematics. We report a detection of this EFE using galaxies from the Spitzer Photometry and Accurate Rotation Curves (SPARC) sample together with estimates of the large-scale external gravitational field from an all-sky galaxy catalog. Our detection is threefold: (1) the EFE is individually detected at 

8σ

$8\sigma$ to 

11σ

$11\sigma$ in "golden" galaxies subjected to exceptionally strong external fields, while it is not detected in exceptionally isolated galaxies, (2) the EFE is statistically detected at more than 

4σ

$4\sigma$ from a blind test of 153 SPARC rotating galaxies, giving a mean value of the external field consistent with an independent estimate from the galaxies' environments, and (3) we detect a systematic downward trend in the weak gravity part of the radial acceleration relation at the right acceleration predicted by the EFE of the MOND modified gravity. Tidal effects from neighboring galaxies in the Λ

$\mathrm{\Lambda }$CDM context are not strong enough to explain these phenomena. They are not predicted by existing Λ

$\mathrm{\Lambda }$CDM models of galaxy formation and evolution, adding a new small-scale challenge to the Λ

$\mathrm{\Lambda }$CDM paradigm. Our results point to a breakdown of the SEP, supporting modified gravity theories beyond General Relativity.

 

Pub Date:

 

September 2020

 

arXiv:

 

arXiv:2009.11525 

 

 

E-Print Comments:

 

ApJ, accepted, 14 figures, 2 tables

A New Top Quark Mass Measurement

The top quark is the most massive fundamental particle in the Standard Model. A new work makes a precision LHC measurement by using clever methods to reduce jet scale associated uncertainty. The bottom line value from the new work is:

m(t) = 172.5 ± 1.2 GeV

This compared to the PDG global average of:

m(t) = 172.4 ± 0.7 GeV

Prior measurements are summarized as follows:

More background is recapped at a previous post at this blog about the top quark mass. 

Theoretical expectations

(1) global electroweak fits favor a top quark mass of:

m(t) = 173.52 ± 0.88 GeV

This is consistent with the Particle Data Group value at a 1 sigma level (given the uncertainties in both the PDG value and the prediction).

But fairly slight adjustments down of the W boson mass from the current estimate of 80.385 ± 0.015 GeV down by one or two standard deviations from this value would favor a somewhat lower global electroweak fit expectation for the top quark mass.

(2) an extended Koide's rule favors a top quark mass of:

m(t) = 173.263 947 ± 0.000 006 GeV

This is consistent with the Particle Data Group value at a 1.2 sigma level.

(3) the expectation of that sum of the square of the fundamental particle masses in the Standard Model is equal to the square of the Higgs vacuum expectation value (using PDG values) favors a top quark mass of about:

m(t) = 173.71 GeV

This is consistent with the Particle Data Group value at a 1.9 sigma level.

The Higgs vacuum expectation value is 246.21965 ± 0.00060 GeV. The Higgs boson mass is currently 125.10 ± 0.14 GeV according to the Particle Data Group 

Increases in the measured value of the Higgs boson mass (currently ) can push this to a somewhat smaller value, although not on a one to one basis, so any adjustment in the Higgs boson mass that is plausible would not shift this down a great deal.

The best fit in terms of deviation from the Particle Data Group values (using an electroweak fit value for the W boson mass) to fit the top quark mass and Higgs boson mass to these relationships at a 1.1 sigma level would be a top quark mass of 173.15 GeV and a Higg boson mass of 125.28 GeV.

(4) the expectation of that sum of the square of the fundamental fermion masses in the Standard Model is equal to half of the square of the Higgs vacuum expectation value favors a top quark mass of:

m(t) = 174.04 GeV.

This is 2.3 sigma higher than the Particle Data Group global average and hence in tension with it, although not absolutely ruled out.

This assumption also favors a Higgs boson mass of 124.65 GeV, which is about 3.3 sigma below the measured value, also in strong tension with the measured value.

So, this fourth theoretical expectation that the sum of the square of fundamental fermion masses equals half of the Higgs vacuum expectation value squared and that the sum of the square of the fundamental boson masses equals half of the Higgs vacuum expectation value squared, is probably not true. We live in a "boson heavy" universe by this measure.

UPDATE: See also this preprint.

[Submitted on 8 Oct 2020]

Simultaneous extraction of αs and mt from LHC tt¯ differential distributions

Amanda M. Cooper-Sarkar, Michal Czakon, Matthew A. Lim, Alexander Mitov, Andrew S. Papanastasiou

We present a joint extraction of the strong coupling αs and the top-quark pole mass mt from measurements of top-quark pair production performed by the ATLAS and CMS experiments at the 8 TeV LHC. For the first time, differential NNLO theory predictions for different values of the top-quark mass are utilised for four kinematic distributions: the average transverse momentum of the top-quark, its average rapidity and the pair invariant mass and rapidity. The use of fastNLO tables for these distributions allows rapid evaluation of the differential theory predictions for different PDF sets. We consider the single differential distributions from the experiments both separately and in combination in order to obtain the best fit to theory. Our final values are αs=0.1159+0.0013−0.0014 and mt=173.8+0.8−0.8 GeV which are compatible with previous extractions using top-quark measurements. In the case of mt, our value is also compatible with the world average value collated by the Particle Data Group.

Comments:	35 pages. Supplementary results available at this http URL
Subjects:	High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
Report number:	CAVENDISH-HEP-20/12, TTK-20-31, P3H-20-051
Cite as:	arXiv:2010.04171 [hep-ph]
	(or arXiv:2010.04171v1 [hep-ph] for this version)