Inflation and the cosmic microwave background

I give a status report and outlook concerning the use of the cosmic microwave background anisotropies to constrain the inflationary cosmology, and stress its crucial role as an underlying paradigm for the estimation of cosmological parameters.Comment: 8 pages LaTeX file, with two figures incorporated using epsf. To appear, proceedings of `The non-sleeping universe', Porto (Astrophysics and Space Science

De Sitter ground state of scalar-tensor gravity and its primordial perturbation

Scalar-tensor gravity is one of the most competitive gravity theory to Einstein's relativity. We reconstruct the exact de Sitter solution in scalar-tensor gravity, in which the non-minimal coupling scalar is rolling along the potential. This solution may have some relation to the early inflation and present acceleration of the universe. We investigated its primordial quantum perturbation around the adiabatic vacuum. We put forward for the first time that exact de Sitter generates non-exactly scale invariant perturbations. In the conformal coupling case, this model predicts that the tensor mode of the perturbation (gravity wave) is strongly depressed.Comment: 9 page

Evidence for a Positive Cosmological Constant from Flows of Galaxies and Distant Supernovae

Recent observations of high-redshift supernovae seem to suggest that the global geometry of the Universe may be affected by a `cosmological constant', which acts to accelerate the expansion rate with time. But these data by themselves still permit an open universe of low mass density and no cosmological constant. Here we derive an independent constraint on the lower bound to the mass density, based on deviations of galaxy velocities from a smooth universal expansion. This constraint rules out a low-density open universe with a vanishing cosmological constant, and together the two favour a nearly flat universe in which the contributions from mass density and the cosmological constant are comparable. This type of universe, however, seems to require a degree of fine tuning of the initial conditions that is in apparent conflict with `common wisdom'.Comment: 8 pages, 1 figure. Slightly revised version. Letter to Natur

Analyzing redshift surveys to measure the power spectrum on large scales

Upcoming large redshift surveys potentially allow precision measurements of the galaxy power spectrum. To accurately measure P(k) on the largest scales, comparable to the depth of the survey, it is crucial that finite volume effects are accurately corrected for in the data analysis. Here we derive analytic expressions for the one such effect that has not previously been worked out exactly: that of the so-called integral constraint. We also show that for data analysis methods based on counts in cells, multiple constraints can be included via simple matrix operations, thereby rendering the results less sensitive to galactic extinction and misestimates of the shape of the radial selection function.Comment: Mostly superseded by astro-ph/9708020; from 5/5-97. 10 pages, with 1 figure included. More detailed treatment at http://www.sns.ias.edu/~max/galpower.html (faster from the US), from http://www.mpa-garching.mpg.de/~max/galpower.html (faster from Europe) or from [email protected]

Small Scale Structure and High Redshift HI

Cosmological simulations with gas dynamics suggest that the Lyman-alpha forest is produced mainly by "small scale structure" --- filaments and sheets that are the high redshift analog of today's galaxy superclusters. There is no sharp distinction between Lyman-alpha clouds and "Gunn-Peterson" absorption produced by the fluctuating IGM -- the Lyman-alpha forest {\it is} the Gunn-Peterson effect. Lyman limit and damped Lyman-alpha absorption arises in the radiatively cooled gas of forming galaxies. At $z~2-3$, most of the gas is in the photoionized, diffuse medium associated with the Lyman-alpha forest, but most of the {\it neutral} gas is in damped Lyman-alpha systems. We discuss generic evolution of cosmic gas in a hierarchical scenario of structure formation, with particular attention to the prospects for detecting 21cm emission from high redshift HI. A scaling argument based on the present-day cluster mass function suggests that objects with M_{HI} >~ 5e11 h^{-1} \msun should be extremely rare at $z~3$, so detections with existing instruments will be difficult. An instrument like the proposed Square Kilometer Array could detect individual damped Lyman-alpha systems at high redshift, making it possible to map structure in the high redshift universe in much the same way that today's galaxy redshift surveys map the local large scale structure.Comment: 15 pages, latex w/ crckapb & epsf macros, ps figures; get ps version with all figures from ftp://bessel.mps.ohio-state.edu/pub/dhw/Preprints To appear in Cold Gas at High Redshift, eds. M. Bremer et al. (Kluwer, 1996

Quintessence-the Dark Energy in the Universe?

Quintessence - the energy density of a slowly evolving scalar field - may constitute a dynamical form of the homogeneous dark energy in the universe. We review the basic idea and indicate observational tests which may distinguish quintessence from a cosmological constant.Comment: 13 pages, 3 figures, LaTe

Randomized phase II study with two gemcitabine- and docetaxel-based combinations as first-line chemotherapy for metastatic non-small cell lung cancer

<p>Abstract</p> <p>Background</p> <p>Docetaxel and gemcitabine combinations have proven active for the treatment of non-small cell lung cancer (NSCLC). The aim of the present study was to evaluate and compare two treatment schedules, one based on our own preclinical data and the other selected from the literature.</p> <p>Methods</p> <p>Patients with stage IV NSCLC and at least one bidimensionally-measurable lesion were eligible. Adequate bone marrow reserve, normal hepatic and renal function, and an ECOG performance status of 0 to 2 were required. No prior chemotherapy was permitted. Patients were randomized to arm A (docetaxel 70 mg/m²on day 1 and gemcitabine 900 mg/m²on days 3–8, every 3 weeks) or B (gemcitabine 900 mg/m2 on days 1 and 8, and docetaxel 70 mg/m2 on day 8, every 3 weeks).</p> <p>Results</p> <p>The objective response rate was 20% (95% CI:10.0–35.9) and 18% (95% CI:8.6–33.9) in arms A and B, respectively. Disease control rates were very similar (54% in arm A and 53% in arm B). No differences were noted in median survival (32 vs. 33 weeks) or 1-year survival (33% vs. 35%). Toxicity was mild in both treatment arms.</p> <p>Conclusion</p> <p>Our results highlighted acceptable activity and survival outcomes for both experimental and empirical schedules as first-line treatment of NSCLC, suggesting the potential usefulness of drug sequencing based on preclinical models.</p> <p>Trial registration number</p> <p>IOR 162 02</p

Phase II study of gemcitabine plus oxaliplatin as first-line chemotherapy for advanced non-small-cell lung cancer

This phase II study evaluated the response rate and tolerability of gemcitabine–oxaliplatin chemotherapy in non-small-cell lung cancer (NSCLC) patients. Chemonaive patients with stage IIIB or IV NSCLC received gemcitabine 1000 mg m−2 on days 1 and 8, followed by oxaliplatin 130 mg m−2 on day 1. Cycles were repeated every 21 days for up to six cycles. From February 2002 to May 2004, 60 patients were enrolled into the study in seven Italian institutions. We observed one complete response (1.7%) and 14 partial responses (23.3%), for an overall response rate of 25.0% (95% confidence interval, 14.7–37.9%). The median duration of response was 5.9 months (range 1.5–17.1 months). With a median follow-up of 6.7 months, median time to progressive disease and overall survival were 2.7 (range 1.9–3.4 months) and 7.3 months (range 7.2–8.6 months), respectively. The main grade 3–4 haematological toxicities were transient neutropenia in 11.7% and thrombocytopenia in 8.3% of the patients. Nausea/vomiting was the main grade 3–4 nonhaematological toxicity, occurring in 10.0% of the patients. Two (3.3%) patients developed grade 3 neurotoxicity. Our results show that gemcitabine–oxaliplatin chemotherapy is active and well tolerated in patients with advanced NSCLC, deserving further study, especially for patients not eligible to receive cisplatin