ScienceNow: Some arguments will never end. A year ago, astronomers reported observations that were widely hailed as proof positive for the existence of dark matter, the mysterious stuff whose gravity holds the galaxies together. But now a different team says that the very same observation can be explained by a controversial theory that rejects dark matter and alters the rules of gravity.
Dark Matter Not a Done Deal?
Categories:
No TrackBacks
TrackBack URL: http://blogs.physicstoday.org/mt/mt-tb.cgi/1950
Search
Categories
- Acoustics (20)
- Arms control and military physics (167)
- Astronomy and cosmology (890)
- Atomic physics (12)
- Biography and personalities (34)
- Biological physics (155)
- Business and industry (298)
- Careers and employment (5)
- Chemical physics and molecular physics (85)
- Classical mechanics and electromagnetism (2)
- Commentary and opinion (101)
- Computational physics (92)
- Condensed matter (119)
- Crystallography (1)
- Culture and entertainment (8)
- Earth sciences (25)
- Education (287)
- Energy policy and R&D (456)
- Engineering and technology (705)
- Environment and climate change (720)
- Everyday Physics (414)
- Facilities and laboratories (210)
- Fluids and rheology (4)
- Government agencies (289)
- History, sociology, and philosophy (52)
- Instrumentation (4)
- Materials science (78)
- Medical physics (98)
- Metrology and fundamental constants (1)
- Microscopy
- Nanoscale science and technology (106)
- Nonlinear science and emergent phenomena
- Nuclear and particle physics (21)
- Optics and photonics (12)
- Planetary and space science (529)
- Plasma physics (2)
- Publishing (4)
- Quantum physics and information (102)
- Science and society (715)
- Science policy and politics (803)
- Scientific societies and awards (4)
- Semiconductors and electronics
- Statistical physics and thermodynamics
- Theoretical physics (1)
Monthly Archives
- November 2011 (13)
- October 2011 (63)
- September 2011 (66)
- August 2011 (70)
- July 2011 (56)
- June 2011 (69)
- May 2011 (84)
- April 2011 (84)
- March 2011 (93)
- February 2011 (76)
- January 2011 (78)
- December 2010 (72)
- November 2010 (77)
- October 2010 (82)
- September 2010 (72)
- August 2010 (88)
- July 2010 (83)
- June 2010 (89)
- May 2010 (81)
- April 2010 (87)
- March 2010 (89)
- February 2010 (74)
- January 2010 (74)
- December 2009 (83)
- November 2009 (81)
- October 2009 (79)
- September 2009 (82)
- August 2009 (88)
- July 2009 (86)
- June 2009 (91)
- May 2009 (81)
- April 2009 (98)
- March 2009 (97)
- February 2009 (80)
- January 2009 (64)
- December 2008 (68)
- November 2008 (65)
- October 2008 (93)
- September 2008 (98)
- August 2008 (110)
- July 2008 (97)
- June 2008 (117)
- May 2008 (122)
- April 2008 (103)
- March 2008 (106)
- February 2008 (87)
- January 2008 (94)
- December 2007 (82)
- November 2007 (96)
- October 2007 (98)
- September 2007 (93)
- August 2007 (98)
- July 2007 (91)
- June 2007 (83)
- May 2007 (89)
- April 2007 (87)
- March 2007 (88)
- February 2007 (81)
- January 2007 (89)
- December 2006 (80)
- November 2006 (80)
- October 2006 (89)
- September 2006 (80)
- August 2006 (92)
- July 2006 (76)
- June 2006 (91)
- May 2006 (83)
- April 2006 (60)
We follow with great interest the current debate on Dark Matter (DM). However, it is known already since Bergman (a student of Einstein) and Wagoner that scalar field model of DM coupled to standard general relativity is conformally equivalent to modified gravity. Thus axion type DM may simulated MOND or vice versa. For more details see
Inflation, bifurcations of nonlinear curvature Lagrangians and dark energy Authors: Eckehard W. Mielke, Fjodor V. Kusmartsev, Franz E. Schunck (Submitted on 9 Apr 2007) Abstract: A possible equivalence of scalar dark matter, the inflaton, and modified gravity is analyzed. After a conformal mapping, the dependence of the effective Lagrangian on the curvature is not only singular but also bifurcates into several almost Einsteinian spaces, distinguished only by a different effective gravitational strength and cosmological constant. A swallow tail catastrophe in the bifurcation set indicates the possibility for the coexistence of different Einsteinian domains in our Universe. This triple unification' may shed new light on the nature and large scale distribution not only of dark matter but also ondark energy’, regarded as an effective cosmological constant, and inflation. Comments: 20 pages, 8 figures, Proceedings of the 11th Marcel Grossmann Meeting (MG11) in Berlin, Germany, July 23-29, 2006 Subjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics (astro-ph) Cite as: arXiv:0704.1135v1 [gr-qc]