Matter Today Research Articles

The inflaton as dark matter

Within the framework of an explicit dynamical model, in which we calculate the radiatively-corrected, tree-level potential that sets up inflation, we show that the inflaton can be a significant part of dark matter today. We exhibit potentials with both a maximum and a minimum. Using the calculated position of the potential minimum, and an estimate for fluctuations of the inflaton field in the early universe, we calculate a contribution to the matter energy density of $(1-2)\times 10^{-47}{\rm GeV}^4$ in the present universe, from cold inflatons with mass of about $6\times 10^9 {\rm GeV}$ . We show that the inflaton might decay in a specific way, and we calculate a possible lifetime that is several orders of magnitude greater than the present age of the universe. Inflaton decay is related to an interaction which, together with a spontaneous breakdown of CP invariance at a cosmological energy scale, can give rise to a neutrino-antineutrino asymmetry just prior to the time of electroweak symmetry breaking.

ASTHMA PHENOTYPES: Wheezy Infants and Wheezy Children

ASTHMA PHENOTYPES: Wheezy Infants and Wheezy Children

The inflaton as dark matter

Within the framework of an explicit dynamical model, in which we calculate the radiatively-corrected, tree-level potential that sets up inflation, we show that the inflaton can be a significant part of dark matter today. We exhibit potentials with both a maximum and a minimum. Using the calculated position of the potential minimum, and an estimate for fluctuations of the inflaton field in the early universe, we calculate a contribution to the matter energy density of $(1-2)\times 10^{-47}\GeV^4$ in the present universe, from cold inflatons with mass of about $6\times 10^9\GeV$. We show that the inflaton might decay in a specific way, and we calculate a possible lifetime that is several orders of magnitude greater than the present age of the universe. Inflaton decay is related to an interaction which, together with a spontaneous breakdown of CP invariance at a cosmological energy scale, can give rise to a neutrino-antineutrino asymmetry just prior to the time of electroweak symmetry breaking.

The smile in endogenous depression

Leon demonstrated the pure endogenousness of Months later, the next depressive bout necescyclical depression. Assistant master at a prA©sitated readmission. It was in the 1950s, when paratory school, he was incapable of work, England became involved in Far Eastern strife, suicidal and needed admission during depresLeon was depressed to near suicide; on a ward sive episodes. But he happened to be well round he looked the picture of misery. But utter between bouts and out of phase for relapse, depression could not obliterate his puckish when a new managerial regime took over-and sense of humour. What is the matter today?, promptly sacked him; even this extreme circumasked. I think, he replied, I think I'm suffering stance precipitated no mood change, except one from Korea,

Cosmic neutrinos from unstable relic particles

We derive constraints on the relic abundance of a generic particle of mass ∼ 1−10 14 TeV which decays into neutrinos at cosmological epochs, using data from the Fréjus and IMB nucleon decay detectors and the Fly's Eye air-shower array. The lifetime of such unstable particles which may constitute the dark matter today is bounded to be greater than ∼ 10 14–10 18 yr, depending on the mass. For lifetimes shorter than the age of the universe, neutrino energy losses due to scattering and the expansion redshift become important and set limits to the ability of neutrino observatories to probe the early universe.

Indirect detection of unstable heavy dark matter

Unstable relics with lifetime longer than the age of the Universe could be the dark matter today. Electrons, photons and neutrinos are a natural outcome of their decay and could be searched for in cosmic rays and in γ-ray and neutrino detectors. I compare the sensitivities of these three types of searches to the mass and lifetime of a generic unstable particle. I show that if the relics constitute our galactic halo and their branching ratios into electron-positrons, photons and neutrinos are comparable, neutrino searches would probe the longest lifetimes for masses ≳ 40 TeV, while electron-positron searches would be better but more uncertain for lighter particles. If instead the relics are not clustered in our halo, neutrinos are more sensitive a probe than γ-rays for masses ≳ 700 GeV. A 1 km 2 neutrino telescope should be able to explore lifetimes up to ∼10 30s while searching for neutrinos from unstable particles above the atmospheric background.

Tuberculosis Patient Care of the Future

To the Editor.— Your EDITORIAL, Care of Tuberculosis Patients: Reprise, may well involve you in a very hot issue with inadequate consideration of all sides of the problem. Physicians engaged in tuberculosis work have resisted closing of facilities and have emphasized the points made in your EDITORIAL, but the truth of the matter today is that the fiscal crisis that exists in every government unit in the country is simply forcing city councils, county supervisors, and state legislators to look to a change in ways of managing tuberculosis as a means of reducing expenditures. And, it is not entirely unreasonable, because very considerable savings can be realized without compromising quality of care, if intelligent reorganization of facilities is undertaken in advance. In former years, and persisting to the present, outpatient facilities for supervision of chemotherapy have been an appendage to inpatient facilities. Outpatient facilities have usually had no real budget

Bradley and Hegel on Shakespeare

HE REFUSAL of critics to take seriously A. C. Bradley's emphatic acknowledgement of his debt to Hegel must appear as an embarrassing paradox to anyone examining the matter today. The growing interest in writings has brought into focus what may prove to be the most interesting aspect of Bradley's work; and the shift in critical sensibilities, within the last fifty years, has cleared away what was purely transient and personal in Bradley's writing, reinforcing its vital core and thus preparing the way for a careful and sympathetic review of what he himself considered to be an important source of inspiration. The opening words of Hegel's Theory of Tragedy can leave no doubt as to Bradley's estimate of the German philosopher:

A Decade of Spanish American Prose Writing

If we were to judge by what we see people reading in the streetcars and on park benches, or by what we observe on inspection of the show windows of bookshops, it might be said that one of the most significant developments in Spanish American prose writing today is the art of translating foreign books.* This last summer, for instance, in Mexico City, riding the busses at the rush hours, I had the impression that most commuters were reading either the Spanish edition of a well known American monthly or other translations, particularly of novels. One, on which a film then showing was based, seemed to be extremely popular. Again, the windows of the bookshops were crammed with translations, from Hemingway to Simenon, from Sartre to Mickey Spillane. The book lists and advertisements of Latin American publishers confirm this impression. The Latin Americans have always read foreign literature, of course, but it seems to me that there is a significant new element in this matter today. In the past an elite read foreign works in the original language, especially if it were French, and translations-like all books-had small printings. Today there is a mass consumption and a mass production of translations. With the increasing literacy rate, French, English, American, and other foreign works, are now being read not only by the intellectuals, genuine or pseudo, but by tens of thousands of people in all walks of life, particularly in the great urban centers. Literary and cultural cosmopolitanism, for so long the privilege of the few, may now be the commonplace of the many. True, for some this may consist of no more than the reading of foreign trash-and much trash is being translated-but for others it may mean the acquisition of real cultural assets from abroad.

A University Library in Action

DURING the past thirty years or so most of our university libraries have developed systems of administration and organisation closely resembling those of large industries. Even in the older foundations today, while that atmosphere of calm which is essential to the contemplative mind is still evident, behind the scenes there pulsates a most efficient organisation, as busily active as any in the most up‐to‐date factory. That this is not apparent to the average reader—who, as we all know, believes that books select, order, purchase, bind, accession, catalogue, classify and shelve themselves—is a tribute to the self‐effacing modesty of our business efficiency which advertises not itself, makes no display of its driving‐force, nor does it use the presumptive jargon of the traveller in useless commodities. On the contrary, our efficiency must create and maintain a most accessible Tower of Périgord in which the receptive minds of the Montaignes of our day, no less than those of the Marconis, may follow their bent with only unobtrusive help and guidance. That this is so competently achieved in our university libraries is the finest testimonial to the present staffs of those libraries. It was one thing to administer a university library two hundred years ago, when books and readers alike were comparatively few and when the demarcation of the whole field of university education was clear: it is quite another matter today, when elimination of circumscribed education is the order. And so, with a limitless field to cover, a vast and ever‐growing organisation to control, university librarians have wisely taken over, modified, and improved systems of organisation originally planned by economists for other ends.