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The answer is yes, even if we assume that there are no creation of matter directly from the dark energy. Although at the present cosmological epoch the amount of the matter that could be thus created is many orders below the threshold of detection. However the associated processes may become relevant in the very very very distant future of the universe.

The pathway is simple: cosmological horizon + quantum mechanics = matter creation. It is the same principle that is behind the Hawking radiation of black holes only on cosmological scales. And unlike Hawking radiation, which decreases the mass of black hole eventually leading to its evaporation, this particle creation is a consequence of unlimited accelerated cosmological expansion and would continue eternally.

The main driving force behind the accelerated cosmological expansion is the dark energy. If we assume that it is truly stable, that it corresponds to nonzero cosmological constant, then eventually the universe would enter the de Sitter phase where the causal patch of the universe would have a stable event horizon with a fixed temperature. If most of other matter inside this patch of the universe decays, most of whatever remained (such as electrons and positrons) are carried away outside cosmological horizon by exponentially expanding universe, black holes evaporate, then at such late times, most of the content of any casually connected patch of the universe would be Gibbons-Hawking radiation at a fixed temperature $T_{\rm dS}= H_{*}/2\pi$, where $H_* = \sqrt{\Lambda/3}$ is the constant Hubble parameter and $\Lambda$ is cosmological constant. This radiation filling the universe is precisely the new created matter and it can potentially contain baryon matter including quite complex structures. Of course for the majority of casual patches its contents would be rather dull: photons/gravitons of extremely large wavelengths and very very rarely occasionally some massive elementary particles. But, as the universe continues its exponential expansion number of such patches would continue to increase. And while the probability of any nontrivial structure in any given local patch remains very small, the overall number of 'tries' would continue to grow. For a So if we wait long enough, among the matter created in this universe could be sentient observers (so called Boltzmann brains). For example, here we have the estimate of a probability for the appearance of a Boltzmann brain as a result of fluctuation: $\exp(-10^{42})$, so the likely time for the first appearance of the Boltzmann brain would be $\exp(10^{42}) \,\text{Gyr}$. And if our universe would exist for unlimited amount of time in the future, then most of sentient observers would be arising from such fluctuations. A lot of people seems to find this (potential) situation disturbing:

• Page, D. N. (2008). Is our universe likely to decay within 20 billion years?. Physical Review D, 78(6), 063535, doi, arXiv.

• Bousso, R., & Freivogel, B. (2007). A paradox in the global description of the multiverse. Journal of High Energy Physics, 2007(06), 018, doi, arXiv.

Such a future state of the universe strictly speaking could not be called a 'heat death' since there is nonzero particle creation at constant positive temperature and since if we wait for long enough time we could observe arbitrarily large fluctuations, however for most of the time almost every causal patch of the universe would be almost empty (compared with the present day universe), so from the point of view of present day life, this state could be called a 'heat coma'.

Of course, at present, the temperature associated with cosmological horizon is many orders of magnitude smaller than the temperatures of supermassive black holes so any matter created by this mechanism would be drowned by the noise of many other processes happening now, so the times when these effects could become relevant are very distant.

The answer is yes, even if we assume that there are no creation of matter directly from the dark energy. Although at the present cosmological epoch the amount of the matter that could be thus created is many orders below the threshold of detection. However the associated processes may become relevant in the very very very distant future of the universe.

The pathway is simple: cosmological horizon + quantum mechanics = matter creation. It is the same principle that is behind the Hawking radiation of black holes only on cosmological scales. And unlike Hawking radiation, which decreases the mass of black hole eventually leading to its evaporation, this particle creation is a consequence of unlimited accelerated cosmological expansion and would continue eternally.

The main driving force behind the accelerated cosmological expansion is the dark energy. If we assume that it is truly stable, that it corresponds to nonzero cosmological constant, then eventually the universe would enter the de Sitter phase where the causal patch of the universe would have a stable event horizon with a fixed temperature. If most of other matter inside this patch of the universe decays, most of whatever remained (such as electrons and positrons) are carried away outside cosmological horizon by exponentially expanding universe, black holes evaporate, then at such late times, most of the content of any causally connected patch of the universe would be Gibbons-Hawking radiation at a fixed temperature $T_{\rm dS}= H_{*}/2\pi$, where $H_* = \sqrt{\Lambda/3}$ is the constant Hubble parameter and $\Lambda$ is cosmological constant. This radiation filling the universe is precisely the new created matter and it can potentially contain baryon matter including quite complex structures. Of course for the majority of causal patches its contents would be rather dull: photons/gravitons of extremely large wavelengths and very very rarely occasionally some massive elementary particles. But, as the universe continues its exponential expansion number of such patches would continue to increase. And while the probability of any nontrivial contents in any given local patch remains very small, the overall number of 'tries' would continue to grow. So if we wait long enough, among the matter created in this universe could be sentient observers (so called Boltzmann brains). For example, here there is an estimate of a probability for the appearance of a Boltzmann brain as a result of fluctuation: $\exp(-10^{42})$, so the likely time for the first appearance of the Boltzmann brain would be $\exp(10^{42}) \,\text{Gyr}$. And if our universe would exist for unlimited amount of time in the future, then most of sentient observers would be arising from such fluctuations. A lot of people seems to find this (potential) situation disturbing:

• Page, D. N. (2008). Is our universe likely to decay within 20 billion years?. Physical Review D, 78(6), 063535, doi, arXiv.

• Bousso, R., & Freivogel, B. (2007). A paradox in the global description of the multiverse. Journal of High Energy Physics, 2007(06), 018, doi, arXiv.

Such a future state of the universe strictly speaking could not be called a 'heat death' since there is nonzero particle creation at constant positive temperature and since if we wait for long enough time we could observe arbitrarily large fluctuations, however for most of the time almost every causal patch of the universe would be almost empty (compared with the present day universe), so from the point of view of present day life, this state could be called a 'heat coma'.

Of course, at present, the temperature associated with cosmological horizon is many orders of magnitude smaller than the temperatures of supermassive black holes not to mention the temperatures of many others astrophysical subsystems, so any matter created by this mechanism would be drowned by the noise of many other processes happening now, so the times when these effects could become relevant are in a very distant future.

The answer is yes, even if we assume that there are no creation of matter directly from the dark energy. Although at the present cosmological epoch the amount of the matter that could be thus created is many orders below the threshold of detection. However the associated processes may become relevant in the very very very distant future of the universe.

The pathway is simple: cosmological horizon + quantum mechanics = matter creation. It is the same principle that is behind the Hawking radiation of black holes only on cosmological scales. And unlike Hawking radiation, which decreases the mass of black hole eventually leading to its evaporation, this particle creation is a consequence of unlimited accelerated cosmological expansion and would continue eternally.

The main driving force behind the accelerated cosmological expansion is the dark energy. If we assume that it is truly stable, that it corresponds to nonzero cosmological constant, then eventually the universe would enter the de Sitter phase where the causal patch of the universe would have a stable event horizon with a fixed temperature. If all other matter inside this patch of the universe decays, black holes evaporate, then at such late times the content of this patch would be Gibbons-Hawking radiation at a fixed temperature $T_{\rm dS}= H_{*}/2\pi$, where $H_* = \sqrt{\Lambda/3}$ is the constant Hubble parameter and $\Lambda$ is cosmological constant. This radiation filling the universe is precisely the new created matter and it can potentially contain baryon matter including quite complex structures. Moreover if we wait long enough among the matter created there could be sentient observers (so called Boltzmann brains). So if our universe would exist for unlimited amount of time in the future, then most of sentient observers would be arising from such fluctuations:

• Page, D. N. (2008). Is our universe likely to decay within 20 billion years?. Physical Review D, 78(6), 063535, doi, arXiv.

• Bousso, R., & Freivogel, B. (2007). A paradox in the global description of the multiverse. Journal of High Energy Physics, 2007(06), 018, doi, arXiv.

Such a state of the universe strictly speaking could not be called a 'heat death' since there is nonzero particle creation at constant positive temperature and since if we wait for long enough time we could observe arbitrarily large fluctuations, however for most of the time almost every causal patch of the universe would be almost empty (compared with the present day universe), so from the point of view of present day life, this state could be called a 'heat coma'.

Of course, at present, the temperature associated with cosmological horizon is many orders of magnitude smaller than the temperatures of supermassive black holes so any matter created by this mechanism would be drowned by the noise of many other processes happening now, so the times when these effects could become relevant are very distant.

The answer is yes, even if we assume that there are no creation of matter directly from the dark energy. Although at the present cosmological epoch the amount of the matter that could be thus created is many orders below the threshold of detection. However the associated processes may become relevant in the very very very distant future of the universe.

The pathway is simple: cosmological horizon + quantum mechanics = matter creation. It is the same principle that is behind the Hawking radiation of black holes only on cosmological scales. And unlike Hawking radiation, which decreases the mass of black hole eventually leading to its evaporation, this particle creation is a consequence of unlimited accelerated cosmological expansion and would continue eternally.

The main driving force behind the accelerated cosmological expansion is the dark energy. If we assume that it is truly stable, that it corresponds to nonzero cosmological constant, then eventually the universe would enter the de Sitter phase where the causal patch of the universe would have a stable event horizon with a fixed temperature. If most of other matter inside this patch of the universe decays, most of whatever remained (such as electrons and positrons) are carried away outside cosmological horizon by exponentially expanding universe, black holes evaporate, then at such late times, most of the content of any casually connected patch of the universe would be Gibbons-Hawking radiation at a fixed temperature $T_{\rm dS}= H_{*}/2\pi$, where $H_* = \sqrt{\Lambda/3}$ is the constant Hubble parameter and $\Lambda$ is cosmological constant. This radiation filling the universe is precisely the new created matter and it can potentially contain baryon matter including quite complex structures. Of course for the majority of casual patches its contents would be rather dull: photons/gravitons of extremely large wavelengths and very very rarely occasionally some massive elementary particles. But, as the universe continues its exponential expansion number of such patches would continue to increase. And while the probability of any nontrivial structure in any given local patch remains very small, the overall number of 'tries' would continue to grow. For a So if we wait long enough, among the matter created in this universe could be sentient observers (so called Boltzmann brains). For example, here we have the estimate of a probability for the appearance of a Boltzmann brain as a result of fluctuation: $\exp(-10^{42})$, so the likely time for the first appearance of the Boltzmann brain would be $\exp(10^{42}) \,\text{Gyr}$. And if our universe would exist for unlimited amount of time in the future, then most of sentient observers would be arising from such fluctuations. A lot of people seems to find this (potential) situation disturbing:

• Page, D. N. (2008). Is our universe likely to decay within 20 billion years?. Physical Review D, 78(6), 063535, doi, arXiv.

• Bousso, R., & Freivogel, B. (2007). A paradox in the global description of the multiverse. Journal of High Energy Physics, 2007(06), 018, doi, arXiv.

Such a future state of the universe strictly speaking could not be called a 'heat death' since there is nonzero particle creation at constant positive temperature and since if we wait for long enough time we could observe arbitrarily large fluctuations, however for most of the time almost every causal patch of the universe would be almost empty (compared with the present day universe), so from the point of view of present day life, this state could be called a 'heat coma'.

Of course, at present, the temperature associated with cosmological horizon is many orders of magnitude smaller than the temperatures of supermassive black holes so any matter created by this mechanism would be drowned by the noise of many other processes happening now, so the times when these effects could become relevant are very distant.

The answer is yes, even if we assume that there are no creation of matter directly from the dark energy. Although at the present cosmological epoch the amount of the matter that could be created is many orders below the threshold of detection. However the associated processes may become relevant in the very very very distant future of the universe.

The pathway is simple: cosmological horizon + quantum mechanics = matter creation. It is the same principle that is behind the Hawking radiation of black holes only on cosmological scales.

The main driving force behind the accelerated cosmological expansion is the dark energy. If we assume that it is truly stable, that is it corresponds to nonzero cosmological constant, then eventually the universe would enter the de Sitter phase where the causal patch of the universe would have a stable event horizon with a fixed temperature. If all other matter inside this patch of the universe decays, black holes evaporate, then at such late times the content of this patch would be Gibbons-Hawking radiation at a fixed temperature $T_{\rm dS}= H_{*}/2\pi$, where $H_* = \sqrt{\Lambda/3}$ is the constant Hubble parameter and $\Lambda$ is cosmological constant. This radiation is the new matter created and it can potentially contain baryon matter etc. Moreover if we wait long enough among the matter created there could be sentient observers (so called, Boltzmann brains). So if our universe would exist for unlimited amount of time in the future, then most of sentient observers would be arising from such fluctuations:

• Page, D. N. (2008). Is our universe likely to decay within 20 billion years?. Physical Review D, 78(6), 063535, doi, arXiv.

• Bousso, R., & Freivogel, B. (2007). A paradox in the global description of the multiverse. Journal of High Energy Physics, 2007(06), 018, doi, arXiv.

Of course, at present, the temperature associated with cosmological horizon is many orders of magnitude smaller than the temperatures of supermassive black holes, so the time when these effects could be relevant are very distant.

The answer is yes, even if we assume that there are no creation of matter directly from the dark energy. Although at the present cosmological epoch the amount of the matter that could be thus created is many orders below the threshold of detection. However the associated processes may become relevant in the very very very distant future of the universe.

The pathway is simple: cosmological horizon + quantum mechanics = matter creation. It is the same principle that is behind the Hawking radiation of black holes only on cosmological scales. And unlike Hawking radiation, which decreases the mass of black hole eventually leading to its evaporation, this particle creation is a consequence of unlimited accelerated cosmological expansion and would continue eternally.

The main driving force behind the accelerated cosmological expansion is the dark energy. If we assume that it is truly stable, that it corresponds to nonzero cosmological constant, then eventually the universe would enter the de Sitter phase where the causal patch of the universe would have a stable event horizon with a fixed temperature. If all other matter inside this patch of the universe decays, black holes evaporate, then at such late times the content of this patch would be Gibbons-Hawking radiation at a fixed temperature $T_{\rm dS}= H_{*}/2\pi$, where $H_* = \sqrt{\Lambda/3}$ is the constant Hubble parameter and $\Lambda$ is cosmological constant. This radiation filling the universe is precisely the new created matter and it can potentially contain baryon matter including quite complex structures. Moreover if we wait long enough among the matter created there could be sentient observers (so called Boltzmann brains). So if our universe would exist for unlimited amount of time in the future, then most of sentient observers would be arising from such fluctuations:

• Page, D. N. (2008). Is our universe likely to decay within 20 billion years?. Physical Review D, 78(6), 063535, doi, arXiv.

• Bousso, R., & Freivogel, B. (2007). A paradox in the global description of the multiverse. Journal of High Energy Physics, 2007(06), 018, doi, arXiv.

Such a state of the universe strictly speaking could not be called a 'heat death' since there is nonzero particle creation at constant positive temperature and since if we wait for long enough time we could observe arbitrarily large fluctuations, however for most of the time almost every causal patch of the universe would be almost empty (compared with the present day universe), so from the point of view of present day life, this state could be called a 'heat coma'.

Of course, at present, the temperature associated with cosmological horizon is many orders of magnitude smaller than the temperatures of supermassive black holes so any matter created by this mechanism would be drowned by the noise of many other processes happening now, so the times when these effects could become relevant are very distant.