Kinetic energy of Bose systems and variation of statistical averages

✍ Scribed by V. I. Yukalov

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 98 KB
• Volume: 3
• Category: Article
• ISSN: 1612-2011
• DOI: 10.1002/lapl.200510065

✦ Synopsis

The problem of defining the average kinetic energy of
statistical systems is addressed. The conditions of applicability
for the formula, relating the average kinetic energy with the mass
derivative of the internal energy, are analysed. It is shown that
incorrectly using this formula, outside its region of validity,
leads to paradoxes. An equation is found for a parametric
derivative of the average for an arbitrary operator. A special
attention is paid to the mass derivative of the internal energy,
for which a general formula is derived, without invoking the
adiabatic approximation and taking into account the mass
dependence of the potential-energy operator. The results are
illustrated by the case of a low-temperature dilute Bose gas.